Meteor Activity Outlook for March 31-April 6, 2012

The following is a slightly edited version of Bob Lunsford’s excellent weekly summary of meteor activity. The original version can be found at the American Meteor Society’s site.

Meteor activity picks up a bit during April as two major showers are active during the month. The first of these, the Lyrids, are active from the 16th through the 25th, with a pronounced maximum on the 22nd. The Eta Aquariids start appearing near the 28th and reach maximum activity during the first week in May. Sporadic rates are low but steady as seen from the mid-northern hemisphere (45 N). Sporadic rates seen from the mid-southern hemisphere (45 S) rise this month toward a maximum in July.

During this period the moon reaches its full phase on Friday April 6th. At that time the moon will be located opposite the sun and will be in the sky all night long. This weekend the waxing gibbous moon will set during the early morning hours, allowing a few hours of dark skies for observing before the start of morning twilight. This window of opportunity shrinks with each passing night until late in the week when the moon is near full and in the sky all night long. The estimated total hourly rates for evening observers this week is near two for observers in the northern hemisphere and three for those south of the equator. For morning observers the estimated total hourly rates should be near seven as seen from mid-northern latitudes and twelve from mid-southern latitudes. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Even rates are reduced during this period due to moonlight.

The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning March 31/April 1. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following showers are expected to be active this week:

The large Antihelion (ANT) radiant is currently located at 13:08 (204) -09. This position lies in central Virgo, four degrees northwest of the first magnitude star Spica (Alpha Virginis). Due to the large size of this radiant, Antihelion activity may also appear from the nearby constellations of Corvus, extreme eastern Hydra, southwestern Bootes, and northern Centaurus as well as Virgo. This radiant is best placed near 0200 local daylight time (LDT), when it lies on the meridian and is located highest in the sky. Rates at this time should be near two per hour no matter your location. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of slow velocity.

Studies of the IMO video database by Sirko Molau and Juergen Rendtel has revealed a weak radiant active in the constellation of Cygnus this time of year. The Zeta Cygnids (ZCY) are active from March 27 through April 13 with maximum activity occurring on April 6. The current radiant position lies at 19:52 (298) +39. This position lies in central Cygnus, six degrees west of the second magnitude star Sadr (Gamma Cygni). The radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon in a dark sky. Due to the northern declination of the radiant, this activity is not well seen from the southern hemisphere. No matter your location, rates at this time are expected to be less than one per hour. At 44km/sec. the Zeta Cygnids would produce meteors of average velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately five sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near one per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near ten per hour as seen from rural observing sites and two per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Evening rates are reduced during this period due to moonlight.

The list below presents a condensed version of the expected activity this week.
Rates and positions are exact for Saturday night/Sunday morning.

Antihelion (ANT) – 13:08 (204) -09   Velocity 30km/sec
Northern Hemisphere – 2 per hr Southern Hemisphere – 2 per hour

Zeta Cygnids (ZCY) 19:52 (298) +39   Velocity 44km/sec
Northern Hemisphere – <1 per hr Southern Hemisphere – <1 per hour

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

Watch the Moon Join the Venus-Jupiter Show!

Two weeks ago Jupiter and Venus had an amazing close approach in the evening sky. Now the two are separated by ~10°. Though Jupiter appears to be the one that is quickly moving further down night after night, it is actually Venus that is quickly moving by ~1° per day to the east relative to the stars. It just so happens that the stars are moving to the west by ~1° per day so Venus appears to be in the same part of the sky relative to the horizon.

Tonight and tomorrow night the Moon joins in the fun. Tonight (evening of March 25) the Moon will pair up with Jupiter while tomorrow night (evening of March 26) it will spend the evening with Venus.

To put the three objects in perspective, here are their distances from Earth for tonight. The Moon is by far the closest object at a distance of 0.0027 AU (~252,000 miles from the center of the Earth). Venus is the next one out at a distance of 0.72 AU (66.9 million miles) which is 265 times further away than the Moon. While distant Jupiter is 5.76 AU away (535 million miles) or 8 times further away than Venus. In case you are wondering, Mars which is visible as a bright red star in the east during the evening is almost the same exact distance away from Earth as Venus (0.72 AU).

Meteor Activity Outlook for March 24-30, 2012

The following is a slightly edited version of Bob Lunsford’s excellent weekly summary of meteor activity. The original version can be found at the American Meteor Society’s site.

As seen from the northern hemisphere, March is the slowest month for meteor activity. No major annual showers are active and only two very weak minor showers produce activity this month. The sporadic rates are also near their annual minimum so there is not much to look forward to this month except for the evening fireballs that seem to peak this time of year from the northern hemisphere. This could be due to the fact the Antiapex radiant lies highest above the horizon this time of year during the evening hours. From the southern hemisphere, activity from the Centaurid complex begins to wane with only the weak activity visible from Norma and perhaps others areas nearby. At least southern sporadic rates are still strong to make the late summer viewing a bit more pleasurable.

During this period the moon reaches its first quarter phase on Friday March 30th. At that time the moon will be located ninety degrees east of the sun and will set near 0100 local daylight time as seen from the mid-northern latitudes. This weekend the waxing crescent moon will only be visible during the early evening hours and will not interfere with meteor observations. The estimated total hourly rates for evening observers this week is near three for observers in the northern hemisphere and four for those south of the equator. For morning observers the estimated total hourly rates should be near seven as seen from mid-northern latitudes and twelve from mid-southern latitudes. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity.

The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning March 24/25. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The large Antihelion (ANT) radiant is currently located at 13:08 (197) -07. This position lies in southern Virgo, five degrees northwest of the first magnitude star Spica (Alpha Virginis). Due to the large size of this radiant, Antihelion activity may also appear from the nearby constellations of Crater, Corvus, extreme eastern Hydra and northern Centaurus as well as Virgo. This radiant is best placed near 0200 local daylight time (LDT), when it lies on the meridian and is located highest in the sky. Rates at this time should be near two per hour no matter your location. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of slow velocity.

This weekend is prime time to try and view any activity from the Zeta Serpentids (ZSE). This shower is active on only five mornings with peak activity occurring on the 24th. Rates would likely be less than one shower member per hour, even at maximum activity. The radiant is located near 7:12 (258) -05. The area of the sky is located in a blank portion of central Ophiuchus, some eight degrees northeast of third magnitude Zeta Ophiuchi. The radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon in a dark sky. At 64km/sec. the Zeta Serpentids would produce mostly swift meteors.

Later in this period, activity from the Zeta Cygnids (ZCY) will begin. This activity is visible from March 27 through April 13 with maximum occurring on April 5. On the 27th the radiant position lies at 19:42 (295) +38. This position lies in western Cygnus, lying directly between the third magnitude stars Delta Cygni and Albireo (Beta Cygni). The radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon in a dark sky. Due to the northern declination of the radiant, this activity is not well seen from the southern hemisphere. No matter your location, rates at this time are expected to be less than one per hour. At 44km/sec. the Zeta Cygnids would produce meteors of average velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately five sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near two per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near ten per hour as seen from rural observing sites and three per hour during the evening hours. Locations between these two extremes would see activity between the listed figures.

The list below presents a condensed version of the expected activity this week.
Rates and positions are exact for Saturday night/Sunday morning.

Antihelion (ANT) – 13:08 (197) -07   Velocity 30km/sec
Northern Hemisphere – 2 per hr Southern Hemisphere – 2 per hour

Zeta Serpentids (ZSE) 17:12 (258) -05  Velocity 64km/sec
Northern Hemisphere – <1 per hr Southern Hemisphere – <1 per hour

Zeta Cygnids (ZCY)   19:42 (295) +38   Velocity 44km/sec
Northern Hemisphere – <1 per hr Southern Hemisphere – <1 per hour

 

Meteor Activity Outlook for March 17-23, 2012

The following is a slightly edited version of Bob Lunsford’s excellent weekly summary of meteor activity. The original version can be found at the American Meteor Society’s site.

As seen from the northern hemisphere, March is the slowest month for meteor activity. No major annual showers are active and only two very weak minor showers produce activity this month. The sporadic rates are also near their annual minimum so there is not much to look forward to this month except for the evening fireballs that seem to peak this time of year from the northern hemisphere. This could be due to the fact the Antiapex radiant lies highest above the horizon this time of year during the evening hours. From the southern hemisphere, activity from the Centaurid complex begins to wane with only the weak activity visible from Norma and perhaps others areas nearby. At least southern sporadic rates are still strong to make the late summer viewing a bit more pleasurable.

During this period the moon reaches its new phase on Thursday March 22th. At that time the moon will be located near the sun and will not be visible at night. This weekend the waning crescent moon will rise during the early morning hours but will not interfere with meteor observations. The estimated total hourly rates for evening observers this week is near three for observers in the northern hemisphere and four for those south of the equator. For morning observers the estimated total hourly rates should be near seven as seen from mid-northern latitudes and thirteen from mid-southern latitudes. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity.

The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning March 17/18. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The large Antihelion (ANT) radiant is currently located at 12:40 (190) -05. This position lies in western Virgo, only three degrees south of the famous third magnitude double star Porrima (Gamma Virginis). Due to the large size of this radiant, Antihelion activity may also appear from the nearby constellations of Crater, Corvus, and eastern Leo as well as Virgo. This radiant is best placed near 0200 local daylight time (LDT), when it lies on the meridian and is located highest in the sky. Rates at this time should be near two per hour no matter your location. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of slow velocity.

The Gamma Normids (GNO) is a weak shower best seen from the southern hemisphere. This shower is only visible south of forty degrees north latitude. The further one is located south (down to 50S) the better the radiant is situated in the sky. Expected rates from the southern hemisphere is currently near one per hour, even with the radiant located high in the sky. The current radiant position lies at 16:56 (254) -51. This position lies in central Norma, three degrees southwest of the fourth magnitude star Gamma Normae. The radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon in a dark sky. At 56km/sec. the Gamma Normids would produce mostly swift meteors.

On Thursday morning, March 22, activity from the Zeta Serpentids (ZSE) may begin to be noticed. This shower is active on only five mornings with peak activity occurring on the 24th. Rates would likely be less than one shower member per hour, even at maximum activity. The radiant is located near 17:05 (256) -04. The area of the sky is located in a blank portion of central Ophiuchus, some eight degrees northeast of third magnitude Zeta Ophiuchi. The radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon in a dark sky. At 64km/sec. the Zeta Serpentids would produce mostly swift meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately five sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near two per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near ten per hour as seen from rural observing sites and three per hour during the evening hours. Locations between these two extremes would see activity between the listed figures.

The list below presents a condensed version of the expected activity this week.
Rates and positions are exact for Saturday night/Sunday morning.

Antihelion (ANT) – 12:40 (190) -05   Velocity 30km/sec
Northern Hemisphere – 2 per hr Southern Hemisphere – 2 per hour

Gamma Normids (GNO) 16:56 (254) -51   Velocity 56km/sec
Northern Hemisphere – <1 per hr Southern Hemisphere – 1 per hour

Zeta Serpentids (ZSE) 17:04 (256) -04   Velocity 64km/sec
Northern Hemisphere – <1 per hr Southern Hemisphere – <1 per hour

 

SWAN Sungrazer Now In SOHO C2 Field

The newly discovered Comet SWAN has now entered the LASCO C2 instrument field on the SOHO spacecraft. This field observes closer to the Sun than the C3 instrument.

The latest C2 images can be found here:

http://sohowww.nascom.nasa.gov/data/realtime/c2/1024/latest.html .

The comet will probably not survive its encounter with the Sun. As a result, it should begin to fade out any hour now.

Two Bright “Stars” in the Evening Sky

[Editor’s note: I notice that lots of people are still finding this 4 month old post. If you are trying to find out what those bright stars (Venus and Jupiter) in the morning eastern sky are (July 2012), go to the front page of this blog at transientsky.wordpress.com for the latest posts.]

If you haven’t seen them yet, I urge you to go out right after nightfall this evening and look to the Southwest. High up in the sky the planets Venus (the brighter one) and Jupiter (fainter but still brighter than any other star in the sky) are passing within 3° of each other (about 6 lunar diameters.

After looking at the pair, turn yourself around 180°. The bright reddish “star” low in the east is another planet, Mars.

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