Evening Planets – August 10

With all of the excitement about this week’s upcoming Perseids display, don’t forget that the early evening hours have their own celestial show.

Take a peek towards the western horizon as soon as it gets dark this evening. Use brilliant Venus to find Mars and Saturn nearby. If you have a clear view close to the horizon you might even be able to see quickly sinking Mercury.

Don’t worry if you miss the show tonight, the planets will be close together for the next week or so. In fact, the Moon will join the fun starting tomorrow night.

Celestial Triangle (+ Mercury and Vesta) – August 6

The early evening planetary show continues tonight. The celestial triangle of Venus, Mars and Saturn should be easy to spot with a good view of the western horizon. Mercury is also visible much closer to the horizon.

Fred Quintao of Brazil pointed out that the large asteroid Vesta is also visible nearby. His image from August 2 shows Vesta to the north of the Venus-Mars-Saturn triangle.

Image of the Vesta near the Venus-Mars-Saturn triangle. Image taken by Fred Quintao from Brazil on August 2, 2010. Credit: Fred Quintao.

Image of the Vesta near the Venus-Mars-Saturn triangle. Image taken by Fred Quintao from Brazil on August 2, 2010. Credit: Fred Quintao.

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For a view of tonight’s alignment see the chart below.

View of the western horizon after darkness falls on the evening of August 6, 2010. Created with Stellarium.

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For those wanting to find Vesta, the following chart is better. Vesta is too faint at magnitude +8.0 to be seen without the help of binoculars or a small telescope. Though not the biggest asteroid, Vesta is intrinsically the brightest due to a very high albedo (meaning it reflects a large fraction [42%] of the light that encounters it).

Fainter chart showing the position of asteroid (4) Vesta on the evening of August 6. Created with Stellarium.

Evening Trio of Planets

Look to the west right after dark this evening to see 3 (and maybe even 4!) planets grouped closely together. Fred Quintao (Brazil) shared his image of the 4 planets taken on August 3rd. Venus is the bright one with Mars and Saturn above and to the right and Mercury below and halfway to the horizon.

Image of Venus, Mars, Saturn and Mercury from Brazil on August 3rd. Credit and courtesy of: Fred Quintao.

Here in the northern hemisphere the ecliptic is at a shallow angle to the horizon. The Stellarium plot below shows the view for tonight. Venus is the brightest object in the sky after sunset so it should be relatively easy to find. Saturn is almost directly above Venus while Mars is further away to the upper left. If you have a clear view of the horizon and look early enough you can also glimpse Mercury.

Later this month after Saturn has sunk out of view, Venus and Mars will make another triple pairing with the bright star Spica. The brightest star in Virgo, Spica is visible to upper right of the current trio.

Star chart for the evening of August 5th. Produced with Stellarium.

In The Sky This Month – August 2010

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of August 2010.

August 2010 Highlights

* Venus, Mars and Saturn close in on each other in the evening sky
* A 2nd trio of Venus, Mars and Spica form at the end of the month
* Perseid meteor shower visible under great conditions
* Mercury has a mediocre evening apparition in July/August (great from SH)
* Comet 10P/Tempel 2 reaches small telescope brightness in the morning sky

Note: If anyone has pictures or observations of these objects/events and want to share them, send me a comment and I’ll post them on the blog.

Planets

Venus, Mars and Saturn – Venus is the brightest “star” visible in the early evening (at magnitude -4.3 to -4.6). Low in the west it sets about 1.9 to 1.5 hours after sunset. Maximum height above the horizon was reached a few months ago. As a result, Venus will appear to sink lower in the sky every night. Still, it will be well placed for easy observing as it is at its brightest this month. If you are located south of the equator, this is a much better apparition and Venus is sitting as high above the horizon as it can get. Regardless, of where you are located it will be hard to miss brilliant -4 magnitude Venus in the west an hour or 2 after sunset.

This month Venus, Mars and Saturn form a tight trio in the early evening sky. On August 8, Venus (magnitude -4.3), Mars (magnitude +1.5) and Saturn (magnitude +1.1) are located within 4.8° of each other.

August 8 - Venus and Saturn within 2.7° of each other
August 13 - Moon passes within 4.2° of Venus, 7.3° of Saturn and 5.5° of Mars
August 19 - Venus and Mars within 1.9° of each othe

Jupiter - Jupiter once again returns to sight as a brilliant star in the east-southeast a few hours after sunset. The magnitude -2.6 planet will get brighter and better place for observing over the next few months. Last year Jupiter made a series of close approaches to Neptune. This year Jupiter will do the same for Uranus. All month long Jupiter will be located within a few degrees of Uranus.

August 27 - Moon passes within 6.7° of Jupiter

Mercury - Mercury is in the midst of a mediocre evening apparition for northern observers. The apparition is a great one for southern hemisphere observers.

August 12 - Moon passes within 2.2° of Mercury

Meteors

Meteor activity is near a yearly maximum in August. The year is usually split in 2 with January through June having low rates with few major showers while July through December (really through the 1st week of January) have high rates with many major showers.

Sporadic Meteors

Sporadic meteors are not part of any known meteor shower. They represent the background flux of meteors. Except for the few days per year when a major shower is active, most meteors that are observed are Sporadics. This is especially true for meteors observed during the evening. During August, 12-18 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

Perseids (PER)

The Perseids are one of 2 showers that are worth getting up early for. This year the Moon will set early in the evening so the prime meteor watching hours will be nice and dark. Based on the their behavior in prior years a broad maximum is expected between 2010 Aug. 12, 18:30 UT and Aug. 13, 7:00 UT. There may even be a little enhancement as we pass through a dust trail ejected by the Perseids’ parent comet, Swift-Tuttle, in 441 AD at 13:19 UT on Aug. 13 (from the work of Mikhail  Maslov). An additional dust trail created in 1479 may also add a few meteors. The enhancements will be small and may only add another 10 or so meteors per hour to the expected maximum rate of 100 per hour.

These rates will only be visible for those under a very dark sky when the radiant is high in the sky. For most of us, rates will be lower due to light pollution. Still, unless you live in a bright major city, you should be able to see a few dozen meteors per hour.

The best time to look will be after about 1-2 am on the night of August 12/13. Meteors will appear to radiate from the constellation of Perseus in the northeast sky.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Starting this month, info on most of the minor showers will be provided on a weekly basis by Robert Lunsford’s Meteor Activity Outlook.

Additional information on these showers and other minor showers not included here can be found at the following sites: Wayne Hally’s and Mark Davis’s NAMN Notes, and the International Meteor Organization’s 2010 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None

Binocular Comets (V = 6.0 – 8.0)

None

Small Telescope Comets (V = 8.0 – 10.0)

Comet 10P/Tempel 2

’10P’ says it all. This was only the 10th comet to be observed at a 2nd apparition meaning we’ve been following this comet for a long time. Discovered by prolific German comet discoverer Ernst Wilhelm Leberecht Tempel in Marseille, France on July 4, 1873, Tempel 2 has been observed at nearly every return since then. The comet’s current orbit brings it to within 1.42 AU of the Sun on July 4 and to within 0.65 AU of Earth in late August.

The comet is currently at a brightness of 9.0 to 9.5 magnitude. This is a large diffuse object so it will be more difficult to see than your average 9th magnitude comet or deep sky object. From my moderately light polluted backyard and 12″ telescope, the comet was a difficult object and was estimated to be magnitude 10.0. From a dark site and 30×125 binoculars, the comet was much brighter (magnitude 9.5), larger and easier to see. The added brightness was probably due to the dark site allowing me to see much more of the comet’s coma.

At mid-month the comet will be 1.49 AU from the Sun and 0.66 AU from Earth. Tempel 2 is a morning object moving from the constellation of Aquarius to Cetus.

A finder chart for Comet Tempel 2 can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Asteroids

Binocular and Small Telescope Asteroids (V < 9.0)

(1) Ceres

Ceres is the biggest asteroid in the Main Belt with a diameter of 585 miles or 975 km. It is so big that it is now considered a Dwarf Planet. Classified as a carbonaceous (carbon-rich) Cg-type asteroid, there are suggestions that it may be rich in volatile material such as water. Some even propose that an ocean exists below its surface. Ceres is the other target of NASA’s Dawn spacecraft which is scheduled to visit it in 2015.

This month Ceres is a month past opposition. The asteroid will start the month at magnitude 8.1 and fade to magnitude 8.6 by the end of the month. All month long it will slowly moving in the constellation Ophiuchus.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Ceres from Heavens Above.

(6) Hebe and (8) Flora

These 2 large inner Main Belt asteroids will move in tandem this fall. Both are S-type asteroids with similar compositions and albedos. (6) Hebe is the larger of the pair (205 x 185 x 170 km). Recent research suggests that it is the source of many ordinary chondrite meteorites and near-Earth asteroids. (8) Flora is a little smaller (136 x 136 x 113 km) and is the largest surviving member of a numerous asteroid family created by a long ago impact.

This month Hebe is retrograding in Cetus and will brighten from magnitude 8.7 to 8.0. Just across the border in Aquarius Flora will brighten from magnitude 9.2 to 8.4.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Hebe from Heavens Above.

In the Sky This Month – July 2010

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of July 2010.

July 2010 Highlights

* Total Solar Eclipse on the 11th for the South Pacific
* Venus, Mars and Saturn close in on each other in the evening sky
* Venus passes within 2° of bright star Regulus on the 8th
* Mars and Saturn within 1.8° of each other on the 30th
* Mercury has a mediocre evening apparition in July/August (great from SH)
* Mercury passes within 0.3° of Regulus on the 27th
* Comet 10P/Tempel 2 reaches small telescope brightness in the morning sky

Note: If anyone has pictures or observations of these objects/events and want to share them, send me a comment and I’ll post them on the blog.

Planets

Venus – Venus is the brightest “star” visible in the early evening (at magnitude -4.2). Low in the west it sets about 2 hours after the Sun. Maximum height above the horizon was reached over a month ago. As a result, Venus will appear to sink lower in the sky every night. Still, it will be well placed for easy observing for the next 2 months. If you are located south of the equator, this is a great apparition and Venus will continue to climb higher till late August. Regardless, of where you are located it will be hard to miss brilliant -4 magnitude Venus in the west an hour or 2 after sunset.

July 10 - Venus within 1.0° of bright star Regulus
July 14 - Moon passes within 5.5° of Venus

Mars – Mars moves rapidly from the constellation of Leo and into Virgo this month. Though fading from magnitude +1.3 to +1.5 it is still an obvious red beacon in the southwest right after sundown. It’s brightness is comparable to that of the other bright stars. Mars starts the month 23° from Venus and 15° from Saturn. By the end of the month, Mars will have caught up to Saturn. Venus isn’t far behind and all three planets will share the same part of the sky in August.

July 16 - Moon passes within 5.6° of Mars
July 30 - Mars and Saturn within 1.8° of each other

Saturn – This month Saturn is located in Virgo and visible in the southwest during the early evening hours. At magnitude +1.1 it is slightly brighter than Mars. The two will be within 2° of each other at the end of the month. Telescope users should note that Saturn’s rings are still within a few degrees of edge-on.

July 16 - Moon passes within 7.4° of Saturn
July 30 - Saturn and Mars within 1.8° of each other

Jupiter - Jupiter once again returns to sight as a brilliant star in the east-southeast before dawn. The magnitude -2.6 planet will get brighter and better place for observing over the next few months. Last year Jupiter made a series of close approaches to Neptune. This year Jupiter will do the same for Uranus. All month long Jupiter will be located within 2-3° of Uranus.

July 3 - Moon passes within 6.5° of Jupiter
July 31 - Moon passes within 6.6° of Jupiter

Mercury - Mercury will start the month too close to the Sun for observation. By mid-month, it starts to peak above the western horizon after sundown.  The apparition is a great one for southern hemisphere observers but a so-so one for northern observers. The

July 12 - Moon passes within 3.9° of Mercury
July 27 - Mercury passes within 0.3° of bright star Regulus

Meteors

Meteor activity should really pick up in July. The year is usually split in 2 with January through June having low rates with few major showers while July through December (really through the 1st week of January) have high rates with many major showers.

Sporadic Meteors

Sporadic meteors are not part of any known meteor shower. They represent the background flux of meteors. Except for the few days per year when a major shower is active, most meteors that are observed are Sporadics. This is especially true for meteors observed during the evening. During JuLy, 10-16 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

No major showers are active this month.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Starting this month, info on most of the minor showers will be provided on a weekly basis by Robert Lunsford’s Meteor Activity Outlook.

Additional information on these showers and other minor showers not included here can be found at the following sites: Wayne Hally’s and Mark Davis’s NAMN Notes, and the International Meteor Organization’s 2010 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None

Binocular Comets (V = 6.0 – 8.0)

None

Small Telescope Comets (V = 8.0 – 10.0)

Comet 10P/Tempel 2

’10P’ says it all. This was only the 10th comet to be observed at a 2nd apparition meaning we’ve been following this comet for a long time. Discovered by prolific German comet discoverer Ernst Wilhelm Leberecht Tempel in Marseille, France on July 4, 1873, Tempel 2 has been observed at nearly every return since then. The comet’s current orbit brings it to within 1.42 AU of the Sun on July 4 and to within 0.65 AU of Earth in late August.

The comet is currently at a brightness of 9.0 to 9.5 magnitude and should brighten by another half magnitude this month. This is a large diffuse object so it will be more difficult to see than your average 9th magnitude comet or deep sky object. From my moderately light polluted backyard and 12″ telescope, the comet was a difficult object and was estimated to be magnitude 10.0. From a dark site and 30×125 binoculars, the comet was much brighter (magnitude 9.5), larger and easier to see. The added brightness was probably due to the dark site allowing me to see much more of the comet’s coma.

Tempel 2 is a morning object moving from the constellation of Aquarius to Cetus.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Comet C/2009 K5 (McNaught)

If you are looking for Comet C/2009 R1 (McNaught), which was a nice bright naked eye comet last month, this Comet McNaught isn’t the comet you’re looking for. C/2009 R1 is now too close to the Sun to be seen. The lesser known, and fainter but more observable, ‘Comet McNaught’  is Comet C/2009 K5 (McNaught). This will probably be the last month to catch a glimpse of this comet in backyard telescopes.

With perihelion back on April 30 of this year at a distance of 1.42 AU from the Sun, C/2009 K5 may still be bright enough to be seen in small backyard telescopes from dark sites. At mid-month it will be located 1.78 AU from the Sun and 2.47 AU from Earth.

Observations over the past month show the comet to be around magnitude 8.5. With the comet in full retreat from the Sun and Earth, it should fade rapidly from here on out. The comet will start the month between 8.5 and 9.0 but should fade to fainter than 10.0 by the end of the month. Due to its located in the northern constellations of Camelopardalis and Lynx, the comet can be seen at all hours of the night from high northern latitudes. It is best in the evening right after the end of twilight.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Asteroids

Binocular and Small Telescope Asteroids (V < 9.0)

(1) Ceres

Ceres is the biggest asteroid in the Main Belt with a diameter of 585 miles or 975 km. It is so big that it is now considered a Dwarf Planet. Classified as a carbonaceous (carbon-rich) Cg-type asteroid, there are suggestions that it may be rich in volatile material such as water. Some even propose that an ocean exists below its surface. Ceres is the other target of NASA’s Dawn spacecraft which is scheduled to visit it in 2015.

This month Ceres will be at opposition and brightest. The asteroid will start the month at magnitude 7.4 and fade to magnitude 8.1 by the end of the month. All month long it will be retrograding on the border of Sagittarius and Ophiuchus.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Ceres from Heavens Above.

Evening Pairing Tonight – Moon and Venus

Tonight the Moon and Venus will make a spectacular pair low in the western sky just after sunset. It will definitely be a sight to see. Tomorrow night (June 15) the Moon will be well above Venus. If you miss out you will have another shot to see the Moon and Venus paired on July 14. Fast forward to August 12 and 13 and the Moon, Venus, Mars and Saturn will all be within a few degrees of each other.

View of the western horizon after darkness falls on the evening of June 14, 2010. Created with Stellarium. Credit: Carl Hergenrother.

Mars and Regulus Make a Nice Pair This Weekend

The evening sky is crowded with bright stars and planets this week. Luckily these bright objects can be seen from almost anywhere, even in the middle of many bright cities. This weekend the planet Mars will make a close approach to the bright star, Regulus.The best time to look is right after twilight in the evening. Watch Mars close in on and pass Regulus. Closest approach is this Sunday night at a little over 0.4 degrees.

At magnitude +1.4 Regulus is about 20% fainter than Mars. Such a small difference in brightness will be hard to notice. More obvious is color difference with Mars red and Regulus blue. The brightest star in Leo, Regulus is about 3.5 times more massive and 150 times brighter than the Sun.

While you’re out there take a peak at brilliant Venus, easily the brightest object in the sky. She will also have here own stellar companions this week. Watch as Venus passes just to the left of the 2 brightest stars in Gemini, Castor and Pollux. The 3rd evening planet is Saturn to the east of Mars/Regulus. Mars, Saturn and Venus will slowly close in on each other for a nice tight triple grouping early in August.

The early evening view this weekend as Mars passes Regulus and Venus approaches Castor and Pollux. Created with Stellarium.

In The Sky This Month – June 2010

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of June 2010.

June 2010 Highlights

* Venus, Mars and Saturn close in on each other in the evening sky
* Comet 2009 R1 (McNaught) reaches naked eye brightness in the morning sky
* Jupiter passes close to Uranus
* Asteroid (1) Ceres at opposition on the 19th and is an easy binocular object
* Partial Lunar Eclipse for the Far East and most of North/South America on the 26th
* Japanese Hayabusa spacecraft to return samples from asteroid Itokawa on the 13th
* EPOXI (spacecraft formally known as Deep Impact) flys past Earth on the 27th

Note: If anyone has pictures or observations of these objects/events and want to share them, send me a comment and I’ll post them on the blog.

Planetary Spacecraft

Hayabusa – On the June 13th, the Japanese Hayabusa spacecraft is scheduled to return to Earth. Tucked away in its sample return capsule may be a few grams of regolith (asteroid soil) from the small Near-Earth asteroid (25143) Itokawa). Launched in 2003, Hayabusa spent a few months in late 2005 studying Itokawa. Though the plan was to retrieve samples of the asteroid for return to Earth, the mission was plagued with many difficulties. As a result, mission operators are unsure if any samples were picked up. Even whether or not the spacecraft can successful hit it target and land in Australia is in doubt. Regardless, the spacecraft and its sample return capsule will be coming back to Earth on the 13th.

NASA will be watching the re-entry of Hayabusa and studying the resulting fireball. Hopefully we will get some great video shortly afterwards. Check out the Hayabusa Re-Entry airborne observing campaign at the SETI Institute and the press releases from the Japanese Aerospace Exploration Agency for the latest.

EPOXI (ex-Deep Impact) -

The main comet event of 2010 will be periodic comet 103P/Hartley 2. Not only will the comet become a nice naked eye object this fall, but a re-used NASA spacecraft will encounter the comet. EPOXI has gone through quite a few name changes in its time. Originally Deep Impact it was launched in January 2005. In July 2005, it released a small package which impacted the surface of periodic comet 9P/Tempel 1. The impact allowed scientists an opportunity to study the interior of a comet. After the conclusion of its primary mission, NASA agreed to fund 2 experiments that utilized the spacecraft. One of its cameras was used to study planets studying other stars (an experiment called EPOCh, for Extrsolar Planet Observation and Charaterization). Also it will fly-by the aforementioned comet Hartley 2 (an experiment called DIXI for Deep Impact eXtended Investigation). Eventually the names were merged into EPOXI but really we are just talking about the old Deep Impact spacecraft.

On the 27th, EPOXI will fly-by the Earth setting up an encounter of Hartley 2 on November 4th.

Planets (and Moon)

Moon – The Moon will experience a Partial Lunar Eclipse on the night of June 25/26. At its best, a little over 53% of the Moon will be in umbral (darkest) eclipse. For the best info on this eclipse go to NASA’s Eclipse Website.

Venus – Venus is the brightest “star” visible in the early evening. Low in the west it sets about 2.5 hours after the Sun. From now till July/August it will ride as high as it’ll get for northern observers. In fact, this is not a great evening apparition for Venus. On the other hand, it is a great apparition for observers south of the Equator. For them, Venus will continue to climb higher till late August. Regardless, of where you are located it will be hard to miss brilliant -4 magnitude Venus in the west an hour or 2 after sunset.

June 11 - Venus in line with bright stars Castor and Pollux
June 15 - Moon passes within 4° of Venus
June 20 - Venus passes the center of the Beehive star cluster

Mars – Mars moves rapidly through the constellation of Leo this month. Though fading from magnitude +1.1 to +1.3 it is still an obvious red beacon to the southwest of overhead right after sundown. It’s brightness is comparable to that of the other bright stars. Watch Mars pass within 0.8° of the bright star Regulus on the 7th. Mars will be magnitude +1.2 on that date and just slightly brighter than Regulus at magnitude +1.4. By the end of the month, Mars is located within 16° of Saturn. The two will be closest at the end of July, and will be joined by Venus in early August.

June 7 - Mars passes 0.8° from the 1st mag star Regulus
June 17 - Moon passes within 6° of Mars

Saturn – This month Saturn is visible in the south during the early evening hours. It will slowly fade from magnitude +1.0 to +1.1 making it slightly brighter than Mars. Telescope users should note that Saturn’s rings are still within a few degrees of edge-on.

June 19 - Moon passes within 8° of Saturn

Jupiter and UranusJupiter once again returns to sight as a brilliant star low in the east-southeast before dawn. The magnitude -2.4 planet will get brighter and better place for observing over the next few months. Last year Jupiter made a series of close approaches to Neptune. This year Jupiter will do the same for Uranus. On June 6th, Jupiter will make it’s first closes approach to Uranus at a small distance of 0.44°.

June 6 - Moon passes within 7° of Jupiter
June 8 - Jupiter passes within 0.5° of Uranus

Mercury -Mercury is in the middle of a morning apparition at the start of the month. This morning apparition will not be good for northern observers though it is excellent for southern observers. By mid-month, Mercury will have fallen back into the glare of the Sun.

June 11 - Moon passes within 9° of Mercury

Meteors

June starts to see an increase in meteor activity after a few months of low activity. The year is usually split in 2 with January through June having low rates with few major showers while July through December (really through the 1st week of January) have high rates with many major showers.

Sporadic Meteors

Sporadic meteors are not part of any known meteor shower. They represent the background flux of meteors. Except for the few days per year when a major shower is active, most meteors that are observed are Sporadics. This is especially true for meteors observed during the evening. During June, 10-16 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

No major showers are active this month.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Starting this month, info on most of the minor showers will be provided on a weekly basis by Robert Lunsford’s Meteor Activity Outlook.

Additional information on these showers and other minor showers not included here can be found at the following sites: Wayne Hally’s and Mark Davis’s NAMN Notes, and the International Meteor Organization’s 2010 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

Comet C/2009 R1 (McNaught)

Comet C/2009 R1 (McNaught) will be a bright binocular comet and probably even a faint naked eye comet for observers under dark skies. Observations made over the past few weeks shows this comet to be rapidly brightening. By the start of June, the comet should be around magnitude 6.5 to 7.0. By mid-month, it will have brightened to magnitude 5.0 and maybe even 4.0. By the end of the month, it will be a bright magnitude 4.0 and perhaps brighter. The lightcurve below shows 3 possible brightness trends that the comet could follow. Though the red curve which shows a peak brightness of magnitude 2 would be nice it is most likely the comet will follow one of the fainter curves and peak at magnitude ~4.

Visual magnitude estimates for C/2009 R1 (as of May 27). Created with COMET. Credit: Carl Hergenrother.

The comet is a morning object and is only visible for an hour or so before the start of dawn. By the end of the month the comet can also be glimpsed in the evening. As the month progresses the comet will become harder to see as it moves closer to the Sun. Observers will need a clear NE (or NW in the evening later in the month) horizon to see the comet. Fourth magnitude is bright enough to be seen with the naked eye under dark conditions. Unfortunately the majority of  us live under bright, murky skies so binoculars will be required to see the comet for most people. The fact that the comet will set will twilight is still bright surely doesn’t help either. Currently the comet is located in Andromeda but it will quickly move through that constellation as well as Perseus and Auriga.

Still inbound, perihelion will occur on July 2nd of this year at a relatively small distance of 0.41 AU from the Sun. This month it will be 0.88 AU from the Sun and 1.26 AU from Earth on June 1st, 0.61 AU from the Sun and 1.14 AU from Earth on the 15th, and 0.41 AU from the Sun and 1.26 AU from Earth on the 30th.

Orbits and position of Comet C/2009 R1 and the planets for June 15, 2010. Image created with C2A. Credit: Carl Hergenrother.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Binocular Comets (V = 6.0 – 8.0)

None

Small Telescope Comets (V = 8.0 – 10.0)

Comet C/2009 K5 (McNaught)

The 2nd ‘Comet McNaught’  is Comet C/2009 K5 (McNaught). It was discovered on May 27, 2009 deep in the southern sky. Similar to C/2009 R1, this comet was also found with the Uppsala schmidt at around magnitude 17.

With perihelion on April 30 of this year at a distance of 1.42 AU from the Sun, C/2009 K5 is still bright enough to be seen in small backyard telescopes from dark sites.   At mid-month it will be located 1.57 AU from the Sun and 2.05 AU from Earth.

Visual magnitude estimates for C/2009 K5 (as of May 30). Created with COMET. Credit: Carl Hergenrother.

Observations over the past 2 months show the comet to be around magnitude 8.0 to 8.5. With the comet in full retreat from the Sun and Earth, it should fade from here on out. The comet will start the month between 8.0 and 8.5 but should fade to around 9.0 by the end of the month. Due to its located in the far northern constellation of Camelopardalis, the comet can be seen at all hours of the night from northern latitudes. It is best in the evening right after the end of twilight.

Orbits and position of Comet C/2009 K5 and the planets for June 15, 2010. Image created with C2A. Credit: Carl Hergenrother.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Asteroids

Binocular and Small Telescope Asteroids (V < 9.0)

(4) Vesta

Vesta is the brightest asteroid in the Main Belt. This is due to its high albedo (or reflectivity) which causes it to reflect ~42% of the light that strikes it. Vesta is also peculiar in that it appears to have evidence of volcanism on its surface. Similar to the Moon, Vesta may be covered with large expanses of frozen lava flows. It is classified as a V-type asteroid and is the only large asteroid with this classification. Many of the smaller V-type asteroids are chips of Vesta blasted off it by past asteroid and comet impacts. Vesta has dimensions of 347x336x275 miles or 578×560×458 km.

The maps below were created from images taken with the Hubble Space Telescope. The geography is dominated by a large impact crater located near the south pole (the blue ‘donut’ in the elevation map). Perhaps this crater is the result of the impact that blasted off the smaller V-type asteroids. We’ll know more next year when NASA’s Dawn spacecraft enters orbit around Vesta for a full year. Currently the encounter is scheduled for July 2011 to July 2012.

Images and models of the shape of asteroid (4) Vesta. In the upper left is a real HST image, to the upper right is a model of Vesta’s shape, and on the bottom is an elevation map . Credit: NASA/STScI.

Vesta starts the month at magnitude 7.7 and steadily fades to mag 7.9. A pair of binoculars will allow you to see Vesta among the stars of Leo.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Vesta from Heavens Above.

(1) Ceres

Ceres is the biggest asteroid in the Main Belt with a diameter of 585 miles or 975 km. It is so big that it is now considered a Dwarf Planet. Classified as a carbonaceous (carbon-rich) Cg-type asteroid, there are suggestions that it may be rich in volatile material such as water. Some even propose that an ocean exists below its surface. Ceres is the other target of NASA’s Dawn spacecraft which is scheduled to visit it in 2015.

Image of Ceres taken with the NASA Hubble Space Telescope. Credit: NASA, ESA, J. Parker (Southwest Research Institute), P. Thomas (Cornell University), and L. McFadden (University of Maryland, College Park)

This month Ceres will be at opposition and brightest. The asteroid will start the month at magnitude 7.5, brighten to magnitude 7.1 at opposition of June 19, and then fade to magnitude 7.4 by the end of the month. All month long it will be retrograding on the border of Sagittarius and Ophiuchus.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Ceres from Heavens Above.

In The Sky This Month – May 2010

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of May 2010. Venus continues to ascend higher in the evening sky and is the brightest star during early evening hours. The major meteor shower, Eta Aquariids, will be washed out by a bright Last Quarter moon.

Note: If anyone has pictures or observations of these objects/events and want to share them, send me a comment and I’ll post them on the blog.

Planets

Venus – Venus is the brilliant star low in the west during the early evening hours. It sets about 2 and half hours after the Sun. Venus will only get a little higher next month. From now till July/August it will ride as high as it’ll get for this apparition for northern observers. In fact, this is not a very good evening apparition for Venus. On the other hand, it is a great apparition for observers south of the Equator. For you, Venus will continue to climb till late August.

May 16 - Moon passes within 0.6° from Venus

Mars – This month the Earth and Mars continue to move further apart. As a result, Mars will continue to fade from magnitude +0.7 to +1.1. Still it will be a bright red beacon nearly overhead right after sundown. It’s brightness is comparable to that of the other bright stars. Note that unlike the stars which twinkle, Mars shines with an unwavering red glow.

May 20 - Moon passes within 5° of Mars

Saturn – Saturn was at opposition in Virgo on March 21. This month Saturn is visible in the east-southeast during the early evening hours. It will slowly fade from magnitude +0.8 to +1.0 throughout the month. Telescope users should note that Saturn’s rings are still within a few degrees of edge-on.

May 22 - Moon passes within 8° of Saturn

JupiterJupiter once again returns to sight as a brilliant star low in the east-southeast before dawn. The magnitude -2.2 planet will get brighter and better place for observing over the next few months.

May 9 - Moon passes within 6° of Jupiter

Mercury -Mercury will rise out of the dawn sky toward the end of the month. This morning apparition will not be good for northern observers.

May 12 - Moon passes within 8° of Mercury

Meteors

May starts to see an increase in meteor activity after a few months of low activity. The year is usually split in 2 with January through June having low rates with few major showers while July through December (really through the 1st week of January) have high rates with many major showers.

Sporadic Meteors

Sporadic meteors are not part of any known meteor shower. They represent the background flux of meteors. Except for the few days per year when a major shower is active, most meteors that are observed are Sporadics. This is especially true for meteors observed during the evening. During May, 10-12 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

Eta Aquariids (ETA)

The Eta Aquarids are a major shower, especially for southern hemisphere observers, when they peak on May 5. For northern observers, the shower will only be observable for an hour or two before dawn. Since the radiant doesn’t get very high for NH observers, rates can be low. The radiant is located near the “jar” of Aquarius.

The ETA were produced by Comet Halley which also gives us the Orionids in October. Models suggest that the ETA were released by Comet Halley no later than 837 AD. The Orionids are easy to see because the particles are hitting the Earth from the anti-solar direction. This means the meteor shower can be seen in the middle of the night. The ETA are produced by meteoroids moving outbound from the Sun, as a result the radiant is located relatively close to the Sun. This means that the ETA radiant is only visible for an hour or so before twilight. By luck, the nearly Full Moon will have just set making the last hour of the night dark.

The shower spans from April 19 to May 28 with a peak around May 5 with a maximum ZHR of ~60.

Additional information on these showers and other minor showers not included here can be found at the following sites: Robert Lunsford’s Meteor Activity Outlook.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Starting this month, info on most of the minor showers will be provided on a weekly basis by Robert Lunsford’s Meteor Activity Outlook.

Additional information on these showers and other minor showers not included here can be found at the following sites: Wayne Hally’s and Mark Davis’s NAMN Notes, and the International Meteor Organization’s 2008 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None

Binocular Comets (V = 6.0 – 8.0)

Comet C/2009 R1 (McNaught)

There are 2 comets bright enough to be seen in small telescopes this month. Both were discovered by Rob McNaught of Australia during the Siding Spring Survey. As a result, both comets go by the moniker of Comet McNaught though they do have different designations [Comet C/2009 K5 (McNaught) and Comet C/2009 R1 (McNaught)].

The comet that should end the month as the brightest is Comet C/2009 R1 (McNaught). This comet was found on Sept. 9, 2009 with the 0.5-m Uppsala Schmidt telescope from Australia. At the time, the comet was a faint 17th magnitude.

Perihelion will be on July 2nd of this year at a relatively small distance of 0.41 AU from the Sun. This month it will be 1.44 AU from the Sun and 1.96 AU from Earth on May 1st, 1.19 AU from the Sun and 1.61 AU from Earth on the 15th, and 0.90 AU from the Sun and 1.28 AU from Earth on the 31st. Currently the comet is around magnitude 10.0 and should brighten to ~7.0 by the end of the month. 10th magnitude requires a small telescope but under dark skies while 7th magnitude should be easy for small telescopes under most sky conditions and binoculars under a dark sky. It is a morning object as it moves from Pisces, through Pegasus and into Andromeda.

This comet may even brighten to naked eye brightness (under very dark skies) in June. Of course with relatively small comets getting this close to the Sun, there is always a chance the comet will break up and disintegrate before it gets too bright (as C/2009 O2 did last month).

Orbits and position of Comet C/2009 R1 and the planets for May 15, 2010. Image created with C2A. Credit: Carl Hergenrother.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Small Telescope Comets (V = 8.0 – 10.0)

Comet C/2009 K5 (McNaught)

The 2nd ‘Comet McNaught’  is Comet C/2009 K5 (McNaught). It was discovered on May 27, 2009 deep in the southern sky. Similar to C/2009 R1, this comet was also found with the Uppsala schmidt at around magnitude 17.

With perihelion on April 30 of this year at a distance of 1.42 AU from the Sun, C/2009 K5 is bright enough to be seen in small backyard telescopes from dark sites. During the month it should be as bright as it gets at around magnitude 8.2 to 9.0. The comet will move through Cepheus and Camelopardalis. As the month progresses, the comet will have traveled far enough north to be circumpolar and visible all night long (for observers at northern mid-latitudes and further north).  At mid-month it will be located 1.44 AU from the Sun and 1.51 AU from Earth.

Orbits and position of Comet C/2009 K5 and the planets for May 15, 2010. Image created with C2A. Credit: Carl Hergenrother.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Asteroids

Binocular and Small Telescope Asteroids (V < 9.0)

(4) Vesta

Vesta is the brightest asteroid in the Main Belt. This is due to its high albedo (or reflectivity) which causes it to reflect ~42% of the light that strikes it. Vesta is also peculiar in that it appears to have evidence of volcanism on its surface. Similar to the Moon, Vesta may be covered with large expanses of frozen lava flows. It is classified as a V-type asteroid and is the only large asteroid with this classification. Many of the smaller V-type asteroids are chips of Vesta blasted off it by past asteroid and comet impacts. Vesta has dimensions of 347x336x275 miles or 578×560×458 km.

The maps below were created from images taken with the Hubble Space Telescope. The geography is dominated by a large impact crater located near the south pole (the blue ‘donut’ in the elevation map). Perhaps this crater is the result of the impact that blasted off the smaller V-type asteroids. We’ll know more next year when NASA’s Dawn spacecraft enters orbit around Vesta for a full year. Currently the encounter is scheduled for July 2011 to July 2012.

Images and models of the shape of asteroid (4) Vesta. In the upper left is a real HST image, to the upper right is a model of Vesta’s shape, and on the bottom is an elevation map . Credit: NASA/STScI.

Vesta starts the month at magnitude 7.3 and steadily fades to mag 7.7. A small pair of binoculars will allow you to see Vesta among the stars of Leo.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Vesta from Heavens Above.

(2) Pallas

Pallas is a dark carbonaceous asteroid though with a slightly bluish B-type spectrum. Due to its high inclination (tilt of its orbit with respect to Earth’s orbit) of 34 degrees it is a difficult target for future spacecraft missions. Pallas is similar in size to Vesta with dimensions of 350x334x301 miles or 582x556x501 km. The reason it is fainter than Vesta is its darker albedo of 16%. Though no spacecraft are scheduled to visit Pallas, Hubble was able to get some good images that clearly show its nearly spherical shape.

This month it fades from magnitude 8.7 to 9.0. Over the course of the month it travels north from the constellation of Serpens Caput into Corona Borealis.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Pallas from Heavens Above.

In The Sky This Month – April 2010

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of April 2010. This first half of the month is a great time to see Mercury, the innermost planet. It can be easily located low in the west during evening twilight right next to Venus.

Note: If anyone has pictures or observations of these objects/events and want to share them, send me a comment and I’ll post them on the blog.

Planets

Mercury and Venus – Venus is the brilliant star low in the west right during evening twilight. It sets an hour and a half after the Sun at the start of the month. By the end of the month, it is up for 2 hours and 15 minutes after sunset. Venus will continue to climb higher and brighten for the next few months.

Mercury is usually difficult to observe. This month, on the other hand, is a perfect time to see this elusive planet. Not only is Mercury as high above the western horizon as it can get for observers in the Northern Hemisphere, but Venus can be used to easily find it. Mercury and Venus are located within 5° of each other until April 12. Mercury is the bright, though still much fainter than Venus, “star” to the lower right of Venus. By the 2nd half of the month, Mercury will be too faint and too close to the Sun to be seen.

Apr 3 - Mercury and Venus within 3° of each other
Apr 8 - Mercury at Greatest Elongation East
Apr 15/16 - Moon passes 4° from Venus and 1.5° from Mercury

Mars – This month the Earth and Mars continue to move further apart. As a result, Mars will continue to fade from magnitude +0.2 to +0.7. Still it will be a brilliant red beacon nearly overhead right after sundown. It’s brightness is comparable to that of the other bright stars. Note that unlike the stars which twinkle, Mars shines with an unwavering red glow.

Apr 17 - Mars within 1.1° of center of Beehive Cluster
Apr 22 - Moon passes close (4°) to Mars

Saturn – Saturn was at opposition in Virgo on March 21. This month Saturn is visible low in the east-southeast during the early evening hours. It will slowly fade from magnitude +0.6 to +0.8 throughout the month. Telescope users should note that Saturn’s rings are still within a few degrees of edge-on.

Apr 25 - Moon and Saturn within 7° of each other

JupiterJupiter once again returns to sight as a brilliant star low in the east-southeast right before dawn. The magnitude -2 planet will get brighter and better place for observing over the next few months.

Apr 11 - Moon and Jupiter within 6° of each other

Meteors

April is still a time of low meteor activity though it will experience a slight uptick in activity due to the Lyrids. The year is usually split in 2 with January through June having low rates with few major showers while July through December (really through the 1st week of January) have high rates with many major showers.

Sporadic Meteors

Sporadic meteors are not part of any known meteor shower. They represent the background flux of meteors. Except for the few days per year when a major shower is active, most meteors that are observed are Sporadics. This is especially true for meteors observed during the evening. During April, 9-11 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

Lyrids (LYR)

April brings the first major meteor shower since the Quadrantids in early January. The Lyrids are produced by Comet Thatcher, a comet on a ~400 years orbit that has only been observed in 1861. The Lyrids, on the other hand, can be seen every year.

The radiant is located between the constellations of Lyra and Hercules. Though the radiant rises during the evening, the best time to see Lyrids is after 11 pm when the radiant is high in the sky.

The shower is active from April 16 to 25 with a peak on the morning of April 22. The shower only shows good levels of activity on the night of the peak. Even then, this is the most minor of the major showers with a peak rate of ~15-25 meteors per hour.

Though there are no predictions on enhanced activity, the Lyrids have been known to put on grand displays. The 1st great display goes back almost 25oo years while the last happened in 1982. So you never know, this year could be the next good display.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Starting this month, info on most of the minor showers will be provided on a weekly basis by Robert Lunsford’s Meteor Activity Outlook.

Additional information on these showers and other minor showers not included here can be found at the following sites: Wayne Hally’s and Mark Davis’s NAMN Notes, and the International Meteor Organization’s 2008 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None

Binocular Comets (V = 6.0 – 8.0)

None

Small Telescope Comets (V = 8.0 – 10.0)

Comet 81P/Wild 2

Comet Wild 2 is a short-period Jupiter-family comet on a 6.4 year orbit. In 1974 a close approach to Jupiter placed the comet on its current orbit which allows (relatively) close approaches to the Sun and Earth. Swiss professional astronomer Paul Wild found the comet photographically on its first close perihelion in 1978. During its last perihelion passage it was the target of the NASA Stardust spacecraft which flew through its coma, collected cometary dust, and returned the dust to Earth. Though Wild 2 has become bright enough to be seen in small backyard telescopes before, this year’s apparition will be its best since discovery. Not till 2042 will it come closer, and even then only marginally so.

The nucleus of comet Wild 2 taken by the Stardust spacecraft. Credit: NASA/JPL/Stardust team.

This year Wild 2 reached perihelion on February 22 at 1.60 AU while closest approach to Earth will occur on April 5 at 0.67 AU. The comet should fade this month but still be as bright as magnitude ~9.0 to 10.0 in April, it should remain brighter than magnitude 10.0 through May. At mid-month the comet a morning object located in Virgo at a distance of 1.68 AU from the Sun and 0.68 AU from Earth.

A finder chart for Comet Wild 2 can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Comet C/2009 K5 (McNaught)

Comet McNaught is the brightest comet in the sky this month. It was discovered by Rob McNaught on the night of May 27, 2009 deep in the southern sky. The discovery was made with the 0.5-m Uppsala Schmidt telescope from Australia as part of the Siding Spring Survey (one of the three Catalina Sky Survey components) for unknown asteroids and comets. At the time, the comet was a faint 17th magnitude.

With perihelion on April 30 of this year at a distance of 1.42 AU from the Sun, C/2009 K5 is now bright enough to be seen in small backyard telescopes from dark sites. During the month it should be as bright as 8.0 to 8.5 magnitude as it moves north while paralleling the Milky Way in Aquila. The comet will be a morning object all month long. At mid-month it will be located 1.44 AU from the Sun and 1.27 AU from Earth.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Comet C/2009 O2 (Catalina)

This long-period comet was supposed to be as bright as magnitude 8 this month but fell short. In fact, images taken since the middle of March suggest the comet may be slowly “fizzling out”. I plan to write a liitle more on this comet and other “disintegrating” comets in a future post.

Asteroids

Binocular and Small Telescope Asteroids (V < 9.0)

(4) Vesta

Vesta is the brightest asteroid in the Main Belt. This is due to its high albedo (or reflectivity) which causes it to reflect ~42% of the light that strikes it. Vesta is also peculiar in that it appears to have evidence of volcanism on its surface. Similar to the Moon, Vesta may be covered with large expanses of frozen lava flows. It is classified as a V-type asteroid and is the only large asteroid with this classification. Many of the smaller V-type asteroids are chips of Vesta blasted off it by past asteroid and comet impacts. Vesta has dimensions of 347x336x275 miles or 578×560×458 km.

The maps below were created from images taken with the Hubble Space Telescope. The geography is dominated by a large impact crater located near the south pole (the blue ‘donut’ in the elevation map). Perhaps this crater is the result of the impact that blasted off the smaller V-type asteroids. We’ll know more next year when NASA’s Dawn spacecraft enters orbit around Vesta for a full year. Currently the encounter is scheduled for July 2011 to July 2012.

Images and models of the shape of asteroid (4) Vesta. In the upper left is a real HST image, to the upper right is a model of Vesta’s shape, and on the bottom is an elevation map . Credit: NASA/STScI.

Vesta starts the month at magnitude 6.8 and steadily fades to mag 7.3. A small pair of binoculars will allow you to see Vesta among the stars in the “Sickle” of Leo.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Vesta from Heavens Above.

(2) Pallas

Pallas is a dark carbonaceous asteroid though with a slightly bluish B-type spectrum. Due to its high inclination (tilt of its orbit with respect to Earth’s orbit) of 34 degrees it is a difficult target for future spacecraft missions. Pallas is similar in size to Vesta with dimensions of 350x334x301 miles or 582x556x501 km. The reason it is fainter than Vesta is its darker albedo of 16%. Though no spacecraft are scheduled to visit Pallas, Hubble was able to get some good images that clearly show its nearly spherical shape.

HST Image of asteroid (2) Pallas. Credit: NASA/STScI.

This month it brightens from magnitude 8.7 to a peak of 8.6 at opposition on April 20. By month’s end, Pallas is back down to magnitude 8.7. Over the course of the month as it travels north through the constellation of Serpens.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Pallas from Heavens Above.

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