In the Transient Sky – May 2012

The big event this month (at least for folks around the northern Pacific basin) is the annular solar eclipse on May 20. As for planets, Venus, Mars and Saturn are easy to see in the evening.

May 2012 Highlights
* Annular Solar Eclipse for western North America, the north Pacific basin and far eastern Asia
* Venus dominates the evening sky
* Mars fades but still is high in the evening sky
* Saturn is easily seen in eastern evening sky
* Comet C/2009 P1 (Garradd) is a nice binocular object in the evening sky

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Annular Solar Eclipse

The big event this month is an annular eclipse of the Sun on May 20. For more information on when and where this event can be seen go to Science News @ NASA Science.

Planets

Evening Planets

Venus  – Venus reaches its maximum brilliance at magnitude -4.7 right at the start of the month. At the start of the month Venus is riding high in the West and sets up to 3.5 hours after the Sun. But Venus is now on a bee-line towards the Sun. By mid-month it sets 2.5 hours after the Sun and by the end of the month it will be so close to the Sun that it sets within 40 minutes of the Sun. All during the month, Venus will slightly fade but in a telescope it will appear to become bigger in apparent diameter while also becoming more crescent. All of this leads up to a rare Venus transit on June 5 when Venus will appear to pass in front of the disk of the Sun. The Moon makes a nice pair with Venus on May 22.

Mars - Mars is the bright reddish “star” nearly overhead early in the evening. Mars reached opposition (the point opposite the Sun on the sky) in early March. Since Mars was near its aphelion when we passed it on our inside track, this opposition is almost as faint as can be at a magnitude of -1.2. In May, it fades from +0.0 to +0.5. The red planet will spend the month moving eastwards below the constellation of Leo. The 1st Quarter Moon visits on the 28th.

Saturn - Saturn reached opposition on April 15 at a distance of 8.75 AU (813 million miles or 1.3 million km) from Earth. Opposition meant Saturn was directly opposite the Sun in the sky. This month it can be seen in the east at the start of evening making a nice but distant pair with bright 1st magnitude Spica. Being past opposition it will fade from magnitude +0.3 to +0.5. The nearly Full Moon visits on the mornings of the 3rd and 4th.

Morning Planets

Mercury – If you live in the Southern Hemisphere, Mercury is still in the middle of a nice morning apparition at the start of the month. By mid-month it will be too low for easy observation.  If, like me, you live north of the equator, this month’s display will be a hard one to observe. At the every end of the month, Mercury starts a better apparition for northern observers in the evening. Though still very low, It will be within ~2° of Venus although both will be only 8° from the Sun at the time.

Jupiter – With conjunction on May 13th, this planet will be located to close to the Sun to be easily seen this month.

Meteors

The year is usually split in 2 with January through June having low rates with few major showers while July through December have high rates with many major showers. Background rates will remain low in May.

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 mornings, 6 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. Unfortunately the Moon is full just a day after the expected peak of the ETAs on May 5 making this a difficult shower to observe this year.

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 and the International Meteor Organization’s 2012 Meteor Shower Calendar.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Info on many minor showers are 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 International Meteor Organization’s 2012 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month.

Binocular Comets (V = 6.0 – 8.0)

C/2009 P1 (Garradd)

First seen way back on August 13, 2009 by Gordon Garradd who was observing for the Siding Spring Survey, a NASA-funded survey observing from Australia. At the time of discovery it was located at a distance 8.7 AU from the Sun, nearly the distance of Saturn. Perihelion occurred 2 days before Christmas 2011 at 1.55 AU from the Sun. Though the comet does not get very close to the Sun, it is an intrinsically bright comet and could have been a real sight had it come closer to the Sun and Earth.

The comet is in full retreat from the Earth and Sun as it heads outward on its long journey back to the cold depths of the outer Solar System.  Comet Garradd is slowly moving south through the constellation of Cancer in the evening sky.  Since the comet is moving away from us and the Sun it should continue to fade from around magnitude 8.0 to 8.9 as the month progresses. The comet does appear to be fading rather slowly and may be brighter than predicted here as the month progresses.

Date       RA       DEC     Delta    r    Elong   Mag
May  1   08h 50m  +38°01'   2.190  2.311    84    8.0
May 10   08h 50m  +33°56'   2.420  2.395    77    8.3
May 20   08h 52m  +30°07'   2.677  2.489    68    8.6
May 30   08h 56m  +26°51'   2.929  2.584    60    8.9

Small Telescope Comets (V = 8.0 – 10.0)

None

In the Transient Sky – April 2012

Though not quite as spectacular as March, 4 planets are visible in the evening this month (Venus, Jupiter, Mars and Saturn).

April 2012 Highlights
* Venus dominates the evening sky
* Jupiter sinks lower into the evening twilight
* Mars fades but rides higher in the evening sky
* Saturn reaches opposition on the 15th
* Comet C/2009 P1 (Garradd) is a nice binocular object in the evening sky
* Mercury is the midst of a relatively poor morning apparition for northern observers and a great apparition for southern observers  

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Evening Planets

Jupiter – The King of the Planets continues to slowly sink into the twilight glow this month. For most of us this will be the last time to spot Jupiter in the evening sky till next year. At magnitude -2.1 to -2.0, it is still the second brightest “star” in the sky after Venus. A very thin and difficult to see Moon will pair up with Jupiter on the evening of March 22.

Venus  – Other than the Moon Venus is the brightest object in the sky. The brilliant beacon is visible high up in the southwest after sunset. Venus starts the month at its highest in the twilight sky and ends the month at its brightest (magnitude -4.7). The real showstopper occurs at the end of the apparition in June when Venus will transit the disk of the Sun. This will be the last Venus transit till 2117. The Moon and Venus make a gorgeous pair on the evening of the 24th.

Mars - Mars is the bright reddish “star” high in the East after evening twilight. Mars reached opposition the point opposite the Sun on the sky) in early March. Since Mars was near its aphelion when we passed it on our inside track, this opposition is almost as faint as can be at a magnitude of -1.2. In April, it fades from -0.7 to -0.1. The red planet will spend the month in the constellation of Leo.

Saturn - Saturn reaches opposition on April 15 at a distance of 8.75 AU (813 million miles or 1.3 million km) from Earth. Opposition means Saturn is directly opposite the Sun in the sky. As a result, it rises around sunset and is highest in the sky at midnight. The Full Moon visits on the mornings of the 7th and 8th.

Morning Planets

Mercury – If you live in the Southern Hemisphere, Mercury will put on a nice display in the morning sky reaching its highest around April 19th. If, like me, you live north of the equator, this month’s display will be a hard one to observe.

Meteors

The year is usually split in 2 with January through June having low rates with few major showers while July through December have high rates with many major showers. March marks the lowest rates of the year.

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 January mornings, 10 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 of early January. The Lyrids were produced by Comet Thatcher, a comet on a ~400 years orbit that has only been observed once back in 1861. The Lyrids meteors, 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. But you never know, this year the Lyrids could put on a good show.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Info on many minor showers are 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 International Meteor Organization’s 2012 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month.

Binocular Comets (V = 6.0 – 8.0)

C/2009 P1 (Garradd)

First seen way back on August 13, 2009 by Gordon Garradd who was observing for the Siding Spring Survey, a NASA-funded survey observing from Australia. At the time of discovery it was located at a distance 8.7 AU from the Sun, nearly the distance of Saturn. Perihelion occurred 2 days before Christmas 2011 at 1.55 AU from the Sun. Though the comet does not get very close to the Sun, it is an intrinsically bright comet and could have been a real sight had it come closer to the Sun and Earth.

The comet is in full retreat from the Earth and Sun as it heads outward on its long journey back to the cold depths of the outer Solar System.  Comet Garradd is slowly moving south through the constellation of Cancer in the evening sky.  Since the comet is moving away from us and the Sun it should continue to fade from around magnitude 7.0 to 7.9 as the month progresses. The comet does appear to be fading rather slowly and may be brighter than predicted here as the month progresses.

Date       RA       DEC     Delta    r    Elong   Mag
Apr  1   09h 34m  +58°01'   1.517  2.047   107    7.0
Apr 10   09h 08m  +50°53'   1.693  2.124   101    7.3
Apr 20   08h 55m  +44°06'   1.919  2.212    93    7.6
Apr 30   08h 50m  +38°31'   2.165  2.302    85    7.9

Small Telescope Comets (V = 8.0 – 10.0)

None

In the Transient Sky – March 2012

Well, I guess this month’s “In the Transient Sky” is better late than never. This month is definitely the “Month of the Planets” in the evening sky. During the beginning of the month, 4 planets are visible (Mercury, Venus, Jupiter and Mars) with a 5th (Saturn) rising later in the evening.

March 2012 Highlights
* Venus and Jupiter have a spectacular conjunction in the SW
* Mars reaches opposition and peak brightness
* Comet C/2009 P1 (Garradd) is a nice circumpolar binocular object

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Evening Planets

Mercury – Mercury starts the month near its maximum elongation in the western evening sky about ~25° to the lower right of much brighter Venus. By the 10th, the innermost planet is diving back into the Sun’s glare. Observers with a clear view of the western horizon may be able to follow Mercury till about the 12th or 13th. Next month it will begin a very poor (for Northern Hemisphere observers) morning apparition. The next Evening apparition will be in June/July.

Venus and Jupiter – Venus is the brilliant beacon in the southwest after sunset. At the end of the month (Mar 27) Venus will be at its highest in the twilight sky. It won’t be at its  brightest will the end of April (Apr 30). The real showstopper occurs at the end of the apparition in June when Venus will transit the disk of the Sun. This will be the last Venus transit till 2117. The Moon and Venus make a gorgeous pair on the evening of the 25th.

Jupiter, the King of Planets, closely shares the evening sky with Venus. By the 10th, the two are located within 4° of each other (8 lunar diameters). They close to within 3° (or 6 lunar diameters) of each other on March 13. Jupiter will continue to fall behind Venus and by month’s end the two will be ~15° apart.

The Moon makes a beautiful pairing with Jupiter on the 25th and Venus on the 26th.

Mars - After admiring Venus and Jupiter, turn around 180° and take a look for Mars, the bright reddish “star” in the East after evening twilight. Mars reached opposition the point opposite the Sun on the sky) on March 3 and is closest to Earth on March 5 at a distance of 0.674 AU or just under 63 million miles (~101 million km). Since Mars was near its aphelion when we passed it on our inside track, this opposition is almost as faint as can be at a magnitude of -1.2. The red planet will spend the rest of the month slowly fading and retrograding towards Regulus in the constellation of Leo.

Morning Planets

Saturn - Kind of the forgotten planet this month is Saturn. At magnitude +0.4 to 0.3 Saturn is located a few degrees to the lower left of the slightly fainter star Spica in Virgo (magnitude +1.0). On the 10th, the ringed planet gets high enough above the eastern horizon for easy observing by 10pm. At the end of the month, Saturn is easily seen around 9pm. The Moon visits on the morning of the 10th and 11th.

Meteors

The year is usually split in 2 with January through June having low rates with few major showers while July through December have high rates with many major showers. March marks the lowest rates of the year.

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 January mornings, 10 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

None this month.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Info on many minor showers are 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 International Meteor Organization’s 2012 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month.

Binocular Comets (V = 6.0 – 8.0)

C/2009 P1 (Garradd)

First seen way back on August 13, 2009 by Gordon Garradd who was observing for the Siding Spring Survey, a NASA-funded survey observing from Australia. At the time of discovery it was located at a distance 8.7 AU from the Sun, nearly the distance of Saturn. Perihelion occurred 2 days before Christmas 2011 at 1.55 AU from the Sun. Though the comet does not get very close to the Sun, it is an intrinsically bright comet and could have been a real sight had it come closer to the Sun and Earth.

The comet is in full retreat from the Earth and Sun this month as it is at the beginning of a long journey back to the cold depths of the outer Solar System. At mid-month it is 1.91 AU from the Sun and 1.30 AU from Earth and by month’s end it will be 2.04 and 1.50 AU from the Sun and Earth, respectively.

Comet Garradd is now a circumpolar object for the Northern Hemisphere meaning it never sets for those of us at Northern mid-latitudes and further north. Racing away from Ursa Minor, the comet will pass to the north and west of the Big Dipper through the “head” of Ursa Major. Since the comet is moving away from us and the Sun it should finally begin to fade from around magnitude 6.8 to 7.7 as the month progresses.

Date       RA       DEC     Delta    r    Elong   Mag
Mar  1   15h 24m  +65°59'   1.272  1.809   106    6.8
Mar 10   13h 23m  +70°35'   1.275  1.873   111    7.0
Mar 20   10h 59m  +67°32'   1.346  1.949   112    7.2
Mar 31   09h 39m  +58°51'   1.500  2.038   108    7.7

Small Telescope Comets (V = 8.0 – 10.0)

None

In the Transient Sky – February 2012

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of February 2012.

February 2012 Highlights
* Venus and Jupiter share the evening sky
* Mars brightens as it approaches opposition
* Comet C/2009 P1 (Garradd) is a nice binocular object during the morning

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Evening Planets

Mercury – Mercury makes an evening appearance during the later half of February. Find Mercury ~30° to the lower right of Venus. The Moon will be close to Mercury on the 22nd.

Venus – Venus is the brilliant beacon in the southwest after sunset. As bright as Venus is it will only get brighter and higher in the sky for the remainder of the winter and into the spring. This year’s evening apparition is as good as it gets with peak visibility in March/April. The real showstopper occurs at the end of the apparition in June when Venus will transit the disk of the Sun. This will be the last Venus transit till 2117. The Moon and Venus make a gorgeous pair on the evening of the 25th.

Jupiter -  The King of Planets shares the evening sky with Venus. It is high in the southeast sky at the end of evening twilight. Past its late October opposition occurred it will slowly fade from magnitude -2.6 to -2.3. Located in Aries, Jupiter will appear to slowly drop lower in the sky and closer to Venus as the month progresses. On Feb 1 Jupiter and Venus are separated by 40°. This distance will shrink every night and by the end of the month they will only be 12° apart. Not that you’ll need the Moon to find Jupiter but the two will make a nice pair on the nights of the 26th and 27th.

Morning Planets

Mars - With opposition in March 2012, Mars double in brightness (magnitude -0.5 to -1.2) as it begins to retrograde near the Leo-Virgo border. Mars rises around 9 pm on the 1st and 7 pm on the 29th. The Moon pairs up with Mars on the morning of the 9th and 10th.

Saturn - Saturn rises three hours after Mars. At magnitude +0.5 Saturn will be located ~7° to the lower right of the slightly fainter star Spica in Virgo (magnitude +1.0). The Moon visits on the morning of the 12th and 13th.

Meteors

Meteor activity starts off high at the beginning of the month but then drops quickly as the month prgresses. The year is usually split in 2 with January through June having low rates with few major showers while July through December 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 January mornings, 10 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

None this month.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Info on many minor showers are 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 International Meteor Organization’s 2012 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month.

Binocular Comets (V = 6.0 – 8.0)

C/2009 P1 (Garradd)

First seen way back on August 13, 2009 by Gordon Garradd who was observing for the Siding Spring Survey, a NASA-funded survey observing from Australia. At the time of discovery it was located at a distance 8.7 AU from the Sun, nearly the distance of Saturn. Perihelion occured 2 days before Christmas 2011 at 1.55 AU from the Sun. Though the comet does not get very close to the Sun, it is an intrinsically bright comet and is already a borderline naked eye object for observers at very dark sites. I was able to observe the comet on the morning of January 2, 2012 with 10×50 binoculars and estimated its brightness at magnitude 6.7. The comet should only be a little brighter this month.

The comet starts the month at a distance of 1.64 AU from the Sun and 1.55 AU from Earth. At mid-month it is 1.71 AU from the Sun and 1.38 AU from Earth and by month’s end it will be 1.80 and 1.28 AU from the Sun and Earth, respectively.  Though the comet is post-perihelion and moving away from the Sun, it is also moving closer to Earth. As a result, the comet should peak in brightness this month.

Traveling north from Hercules through Draco, Comet Garradd is best in the early morning though it will be a circumpolar object by the end of the month.

Date       RA       DEC     Delta    r    Elong   Mag
Feb 1    17h 17m  +41°17'   1.548  1.642    77    6.5
Feb 15   16h 51m  +52°20'   1.377  1.714    91    6.4
Feb 29   15h 33m  +65°10'   1.275  1.802   105    6.5

Small Telescope Comets (V = 8.0 – 10.0)

None

In the Transient Sky – January 2012

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of January 2012.

January 2012 Highlights
* Venus and Jupiter share the evening sky
* Comet C/2011 W3 (Lovejoy) remains a nice, though fading, naked eye object for southern observers
* Comet C/2009 P1 (Garradd) is a nice binocular object during the morning
* Quadrantid meteor shower peaks on the 4th

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Evening Planets

Venus – Venus is the brilliant beacon in the southwest after sunset. As bright as Venus is it will only get brighter and higher in the sky for the remainder of the winter and into the spring. This year’s evening apparition is as good as it gets with peak visibility in March/April. The real showstopper occurs at the end of the apparition in June when Venus will transit the disk of the Sun. 2012 marks the last Venus transit till 2117. The Moon pairs up with Venus on the evenings of 25th and 26th.

Jupiter -  The King of Planets shares the evening sky with Venus. It is high in the southeast sky at the end of evening twilight. Past its late October opposition occurred it will slowly fade from magnitude -2.6 to -2.3. This month it resumes moving prograde through the constellation of Aries. Not that you’ll need the Moon to find Jupiter but the two will make a nice pair on the nights of the 1st-3rd and 29th-30th.

Morning Planets

Mars - With opposition in March 2012, Mars double in brightness (magnitude +0.2 to -0.5) as it begins to retrograde near the Leo-Virgo border. Mars rises around 11 pm on the 1st and 9 pm on the 31st. The Moon pairs up with Mars on the mornings of the 12th and 13th.

Saturn - Saturn rises 3 hours after Mars. At magnitude +0.7 Saturn will be located ~6-7° to the lower right of the slightly fainter star Spica in Virgo (magnitude +1.0). The Moon visits on the morning of the 16th.

Mercury – Mercury starts off the new year at  the tail end of a rather good morning apparition. By mid-month it has sunk back into the glow of dawn.

Meteors

Meteor activity starts off high at the beginning of the month but then drops quickly as the month prgresses. The year is usually split in 2 with January through June having low rates with few major showers while July through December 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 January mornings, 10 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

Quadrantids (QUA)[Max Date = Jan 4, Max ZHR = ~60-200 per hour]

The Quadrantids are the best shower that you’ve probably never heard of. It’s bad enough that this shower peaks in the middle of winter in the northern hemisphere, but it is also named after a long defunct constellation. When first identified in the early 1800s, the meteors were observed to radiate from the small faint constellation of Quadrans Muralis (the Mural Quadrant). Unfortunately, the constellation didn’t make the cut when the official list of 80 constellations was set in 1930. Today, Quadrans Muralis and the radiant of the Quadrantids can be found on the northern reaches of the constellation Bootes.

Another strike against observing the Quadrantids is their short duration. Most showers, like the Perseids and Orionids, produce high rates of meteors for a few days near their maximum. The Quadrantids are only highly active for 12-24 hours. As a result, the shower can be missed if the peak does not coincide with your early morning observing.

The peak time for this shower is always uncertain on the order of half a day or so and the IMO prediction calls for a peak at 7:20 UT on Jan 4 though this time could be off be 12 hours or more. Observers in Europe and the Americas will be well placed for seeing this year’s peak. Unfortunately observers south of the Equator will not see much from the Quadrantids.

Back in 2009 this shower put on a great show with the peak well observed from the US. Peak rates that year reached a ZHR of ~150-160. But in 2008 and 2011, rates “only” reached into the 80s. The Moon will be a problem until it sets around 3 am. Then again the radiant only gets high enough for easy observing after 3 am so the Moon is not much of a problem.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Info on many minor showers are 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 International Meteor Organization’s 2012 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

C/2011 W3 (Lovejoy)

The Surprise Comet of 2011 proved the experts wrong and became the most spectacular comet since Comet C/2006 P1 (McNaught) in 2007. Terry Lovejoy is no stranger to new comets and C/2011 W3 marks his 3rd comet discovery. The Australian amateur used an 8″ telescope and CCD camera to first spot the comet on November 27. Though a diffuse relatively faint 11-12th magnitude object at discovery it was rapidly approaching the Sun. In fact, Comet Lovejoy is a member of the Kreutz sungrazing family of comets which can pass extremely close to the Sun. A small number of Kreutz sungrazers have been seen from the ground over the past 1000 years and a few have ranked as some of the best comets of all time (1106, 1843, 1880, 1882, 1887, 1965). The last Kreutz to be seen from the ground was Comet White-Ortiz-Bolelli in 1970. Since then over 2000 faint “pygmy” sungrazers have been observed close to the Sun by Sun-watching spacecraft.

Based on the apparent faintness of C/Lovejoy as it approached perihelion on December 16 at a distance of only 87,000 miles (140,000 km), it was not expected to survive long past perihelion. Surprisingly the comet did survive after showing some odd behavior near the Sun (comet appeared to fade at perihelion only to rebrighten hours later also it appeared to loss its tail until a new one formed). Due to the orientation of its orbit relative to Earth, the comet is currently only observable from the Southern Hemisphere. A number of southern observers were able to see the comet as a brilliant long tailed object of negative magnitude. Even now the tail is being reported between 20 and 40° in length. The head has rapidly faded suggesting the nucleus has either decreased greatly in activity or even broken up.

Racing away from the Sun the comet will travel across a large swatch of the southern sky this month. For northern observers we may have a chance to see what’s left of Lovejoy towards the end of the month as the comet moves north through the dim constellations of Pictor and Caelum.

Here’s Comet Lovejoy in all its glory as seen from the International Space Station and imaged by astronaut Dan Burbank.

Comet Lovejoy is visible near Earth's horizon in this nighttime image photographed by NASA astronaut Dan Burbank, Expedition 30 commander, onboard the International Space Station on Dec. 22, 2011. Credit: NASA/Dan Burbank.

Additional photos of Comet Lovejoy can be found at the sites of Seiichi Yoshida, Astronomical Society of Victoria, and Cometography (Gary Kronk).

Binocular Comets (V = 6.0 – 8.0)

C/2009 P1 (Garradd)

Until the arrival of Comet Lovejoy, Comet C/2009 P1 (Garradd) held the title of brightest comet of 2011.  First seen way back on August 13, 2009 by Gordon Garradd who was observing for the Siding Spring Survey, a NASA-funded survey observing from Australia. At the time of discovery it was located at a distance 8.7 AU from the Sun, nearly the distance of Saturn. Perihelion occured 2 days before Christmas 2011 at 1.55 AU from the Sun. Though the comet does not get very close to the Sun, it is an intrinsically bright comet and is already a borderline naked eye object for observers at very dark sites. I was able to observe the comet on the morning of January 2, 2012 with 10×50 binoculars and estimated its brightness at magnitude 6.7.

The comet starts the month at a distance of 1.56 AU from the Sun and 1.94 AU from Earth. At mid-month it is 1.58 AU from the Sun and 1.76 AU from Earth and by month’s end it will be 1.64 and 1.56 AU from the Sun and Earth, respectively.  Though the comet is post-perihelion and moving away from the Sun, it is also moving closer to Earth. As a result, the comet should brighten a little more this month.

Traveling north to the left of the ‘keyhole’ of Hercules, Comet Garradd is an early morning object this month.

Date       RA       DEC     Delta    r    Elong   Mag
Jan 1    17h 30m  +26°50'   1.936  1.555    53    6.6
Jan 16   17h 27m  +32°23'   1.762  1.584    63    6.5
Jan 30   17h 18m  +40°37'   1.561  1.638    76    6.4

Small Telescope Comets (V = 8.0 – 10.0)

None

2011 October Monthly Highlights

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of October 2011.

October 2011 Highlights
* Draconid meteor shower may produce high rates over Europe and Asia on the 8th
* Jupiter is at opposition on the 28th
* Comet C/2009 P1 (Garradd) is a nice binocular object during the evening
* Orionid meteor shower peaks on the 21st

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Evening Planets

Mercury – Mercury spends the later half of the month in a poor evening apparition. Usually such a poor apparition wouldn’t be worth observing but this month Venus can be used to find Mercury. Use the Moon to find low but brilliant (magnitude -3.9) Venus and even lower and fainter (magnitude -0.3) Mercury on the evenings of October 27 and 28.

Venus – After spending the past month or so too close to the Sun to be observed, Venus is now starting its slow crawl into the evening sky. Its elongation from the Sun grows from 13° to 20° in October. Still you will need a clear view of horizon to catch Venus low in the WSW during early twilight. Use the Moon to find low but brilliant (magnitude -3.9) Venus and even lower and  fainter (magnitude -0.3) Mercury on the evenings of October 27 and 28.

Jupiter -  The King of Planets is the King of the Night Sky this month. With the other 4 naked eye planets hugging the twilight horizon or rather faint, Jupiter is by far the brightest and best placed. Rising a little over an hour after sunset on the 1st and right at sunset on the 31st, it is at its best around midnight. Opposition occurs on October 28 when Jupiter will peak in brightness at a magnitude of -2.9. For the entire month it will be slowly retrograding in the constellation of Aries. Not that you’ll need the Moon to find Jupiter but the two will make a nice pair on the nights of the 12th and 13th.

Morning Planets

Mars - With opposition in March 2012, Mars continues to slowly brighten (magnitude +1.3 to +1.1) as it moved from Cancer into Leo this month. Mars rises after midnight and is best just before dawn. If you are out watching the Orionids, Mars will be the bright ruddy star near the Moon on the mornings of the 19th and 20th.

Saturn - Saturn passes conjunction on the far side of the Sun at mid-month (Oct 13). Those with very clear eastern horizons may be able to see Saturn an hour before sunrise by the end of the month. Saturn (magnitude +0.7) will be located ~5° to the lower right of the slightly fainter star Spica (magnitude +1.0).

Meteors

Meteor activity is still near a seasonal high in October. The year is usually split in 2 with January through June having low rates with few major showers while July through December 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 October mornings, 10 or so Sporadic meteors can be observed per hour from a dark moonless sky. The Taurids should also contribute another 2-5 meteors per hour all night long.

Major Meteor Showers

Draconids (Giacobinids) (GIA) [Max Date = Oct 8, Max ZHR = highly uncertain between 50 and 600 per hour]

On October 8th at ~20 hours UT, the Draconid meteor shower may produce an outburst of meteors for observers in Europe and Asia. While normally a weak shower, the Draconids put on two of history’s best meteor storms in 1933 and 1946. In those years rates as high as 10,000 per hour were seen. More recently an outburst in 1998 produced a few hundred meteors per hour. This year the Earth will cross dust trails produced by Comet 21P/Giacobini-Zinner in 1900 and 1907, the same two trails that produced the 1933 and 1946 storms, as well as older trails back to 1866. Due to the older age and dispersion of these streams, a major storm is not possible this year. Still ZHRs as high as a few hundred per hour may be possible. The actual number of meteors seen by observers will be much less due to the nearly Full Moon. As a result, the shower may “only” appear as good as the Perseids or Geminids at their peak under a Moon-less sky.

If you’re like me and live in North America, well, we are probably out of luck. Chances are we will see little or no enhancement from the dust trail crossings. This will probably only be a good show for those in Europe, Asia and northern Africa. A map of visibility and much more information on this year’s shower cab be found at the International Meteor Organization’s (IMO) 2011 Draconids site.

Orionids (ORI) [Max Date = Oct 21, Max ZHR = ~35-45 per hour]

The Orionids are one of the most reliable and productive showers of the year. Another point in their favor is their high level of activity over the course of ~5 nights or so. This gives ample opportunity to catch a few Orionid meteors. This year the just past Third Quarter Moon will hamper meteor watching somewhat.

The meteors that make up the Orionid shower were originally released by the one comet everyone has heard of, Comet Halley. Computer simulations of the past movements of Halley and its dust suggest that many of this year’s Orionid meteors were released by Halley between 1265 BC and 910 BC (for some points of reference, the Trojan War took place around 1200 BC and King David ruled around 1000 BC).

The Orionids are usually active from Oct 3 to Nov 11 with a broad peak between Oct 18 and 24. During their peak, rates can be as high as 20-70 meteors per hour. During the last two years ZHRs reached 35-45 meteors per hour which is nearly half the rate observed in 2007 (70 per hour). This year’s activity should be similar to the last few years. With a Moon-lit sky, actual rates will be somewhat lower.

The Orionids appear to come from an area in northern Orion. This area, called the radiant, rises around 10pm local time. It is best to wait till the radiant is high in the sky before looking for meteors (say 1am). The radiant is highest around 3:30am which is the best time to look. As you can see on the sky chart, the Moon is almost on top of the radiant. Meteors can appear anywhere in the sky so you don’t have to look at the radiant.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Info on many minor showers are 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 International Meteor Organization’s 2011 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month…

Binocular Comets (V = 6.0 – 8.0)

C/2009 P1 (Garradd)

The brightest comet of the year is long-period comet C/2009 P1 (Garradd). First seen way back on August 13, 2009 by Gordon Garradd who was observing for the Siding Spring Survey, a NASA-funded survey observing from Australia. At the time of discovery it was located at a distance 8.7 AU from the Sun, nearly the distance of Saturn. Perihelion will occur 2 days before Christmas 2011 at 1.55 AU from the Sun. Though the comet does not get very close to the Sun, it is an intrinsically bright comet and is already a borderline naked eye object for observers at very dark sites (6th magnitude).

The comet starts the month at a distance of 1.92 AU from the Sun and 1.70 AU from Earth. At mid-month it is 1.81 AU from the Sun and 1.87 AU from Earth and by month’s end it will be 1.72 and 2.01 AU from the Sun and Earth, respectively.  Visual observers are placing the comet at magnitude 6.6 to 6.8 at the end of September. It should slightly brighten this month as it slowly moves west in Hercules.

Date       RA       DEC     Delta    r    Elong   Mag
Oct 1    18h 09m  +19°23'   1.697  1.921    87    6.7
Oct 16   17h 49m  +18°51'   1.866  1.811    71    6.6
Oct 31   17h 37m  +18°44'   2.005  1.716    59    6.6

Small Telescope Comets (V = 8.0 – 10.0)

45P/Honda-Mrkos-Pajdusakova

First seen in 1948 by Japanese amateur Minora Honda, Czech astronomer Antonin Mrkos and Slovak astronomer Ludmilla Pajdusakova, this comet is on its 11th observed return since discovery (it was missed during the 1959 and 1985 returns). It is an intrinsically faint Jupiter-family comet which passes within 0.53 AU of the Sun every 5.25 years. This time perihelion passage occurred on September 28. Prior to perihelion the comet made a close approach to within 0.06 AU of Earth which was only easily visible from the Southern Hemisphere. During the next return in 2016/2017, 45P will pass within 0.08 AU of Earth on its outbound leg and will be much better placed for northern observers.

Being after perihelion, the comet will rapidly fade as it moves away from the Sun and Earth as it moves through the constellation of Leo. At the start of the month, it should still be a binocular comet at magnitude 7.6 but will be lost to binoculars within a week or so. At an elongation of 32-37° it can only be seen low on the horizon before dawn.

Date       RA       DEC     Delta    r    Elong   Mag
Oct 1    10h 26m  +08°27'   0.827  0.532    32    7.6
Oct 16   11h 17m  +05°26'   1.139  0.641    34    9.9
Oct 31   12h 03m  +01°40'   1.380  0.839    37   12.7

 

 

In The Sky This Month – June 2011

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of June 2011.

June 2011 Highlights
* Saturn is easy to spot in the evening
* Jupiter is a sight to see just before dawn
* Comet Garradd begins a many month stretch brighter than mag 10

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Moon - The table below lists important lunar dates for the month, including the phases of the Moon and nights of lunar-planetary and lunar-stellar conjunctions.

Jun 1 - New Moon and Partial Solar Eclipse for high latitudes
Jun 5 - Moon 9° from bright star Pollux
Jun 6 - Moon 5° from Beehive Cluster
Jun 7 - Moon 5° from bright star Regulus
Jun 9 - First Quarter
Jun 10 - Moon 8° from Saturn
Jun 11 - Moon 3° from bright star Spica
Jun 14 - Moon 4° from bright star Antares
Jun 15 - Full Moon and Total Eclipse of the Moon (Africa, Asia, Australia)
Jun 23 - Last Quarter Moon
Jun 26 - Moon 5° from Jupiter
Jun 28 - Moon 2° from Mars and Pleiades
Jun 29 - Moon 7° from Aldebaran

Evening Planets

Mercury – Mercury starts the month very low in the ENE dawn sky but is quickly lost over the next few days. It doesn’t take long to reappear and by the last week of June it can be seen low in the WNW 45 minutes or so after sunset. During the last few nights of the month, Mercury makes a nice trio with the bright stars of Gemini, Castor and Pollux. All three can be seen in a 11° long straight line on June 30.

Saturn – Saturn is now well past opposition at magnitude +0.8. It starts the night near its highest point on the meridian to the south. The planet is observable for the rest of the evening.  Saturn is a slow moving planet and takes 29 years to circle the Sun as well as 29 years to do one circuit around the ecliptic constellations. As has been the case all year long, Saturn is still located in Virgo about 13-14° from 1st magnitude Spica. The planet is making a nice “double star”  with 3rd magnitude Gamma Virginis. The two are within 0.25° of each other on June 9.

Jun 10 - Saturn and Moon 8° apart

Morning Planets

Jupiter -  Jupiter rises 2 to 3 hours before sunrise and is well up in  the eastern sky as dawn begins. Shining at magnitude -2.2 the King of the Planets will be the brightest ‘star’ in the sky over the next few months.

Jun 26 - Moon 5° from Jupiter

Mars -  Located 16° to the lower left of Jupiter at the start of the month, the gap increases all month long. Mars is a fast moving planet meaning it does a good job of keeping up with the Sun and as a result will only slowly rise higher in the sky from month to month. Though a relatively faint magnitude +1.4 (for a planet), it will get much brighter as it moves towards opposition in March 2012.

Jun 28 - Moon 2° from Mars

Venus - Venus will be a very difficult sight low in the ENE during dawn. Towards the end of the year, it will be a much easier sight as an evening object.

Meteors

Meteor activity is still near a seasonal minimum in June. The year is usually split in 2 with January through June having low rates with few major showers while July through December 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 mornings, 10-12 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

None 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 2011 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month…

Binocular Comets (V = 6.0 – 8.0)

None this month…

Small Telescope Comets (V = 8.0 – 10.0)

C/2009 P1 (Garradd)

Last month I mentioned how there always seems to be a bright Comet McNaught or Comet Garradd in the sky. Well last month’s Comet McNaught (C/2011 C1) has now faded below 10th magnitude but it has been replaced by a Comet Garradd (C/2009 P1). First seen way back on August 13, 2009 by Gordon Garradd, this is yet another discovery by the Siding Spring Survey, a NASA-funded survey observing from Australia. At the time of discovery it was located at a distance 8.7 AU from the Sun, nearly the distance of Saturn. Perihelion will occur 2 days before Christmas 2011 at 1.55 AU from the Sun. Though the comet does get very close to the Sun, it is an intrinsically bright comet and may be a borderline naked eye object for observers at very dark sites (6th magnitude).

The comet starts the month at a distance of 3.04 AU from the Sun and 2.96 AU from Earth. At mid-month it is 2.91 AU from the Sun and 2.58 AU from Earth and by month’s end it will be 2.76 and 2.19 AU from the Sun and Earth, respectively.  Visual observers are placing the comet at magnitude 10.0 to 10.5 at the end of May. It should brighten to magnitude 9.0 to 9.5 by the end of the month as it slowly moves north near the Pisces/Aquarius border.

Asteroids

Binocular and Small Telescope Asteroids (V < 8.0)

(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 this summer when NASA’s Dawn spacecraft enters orbit around Vesta for a full year. Currently the encounter is scheduled for July 2011 to July 2012 though images showing more details than those from HST may be released this month.

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 spends the month around magnitude 6.9 to 6.3 as it begins its retrograde loop in western Capricornus. Opposition is on August 4 at magnitude 5.6.

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.