Meteor Activity Outlook for February 4-10, 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.

February offers the meteor observer in the northern hemisphere a couple of weak showers plus falling sporadic rates. This may not seem too exiting but you never know when surprises are in store. An errant earthgrazer from the Centaurid complex may shoot northward. Better yet, a bright fireball may light up the sky. February is the start of the fireball season, when an abundance of fireballs seem to occur. This lasts well into April and seems to occur mostly during the early evening hours.

Observers in the southern hemisphere are treated to the Alpha Centaurid peak on the 8th plus the entire Centaurid complex of radiants is active all month long. Sporadic rates also peak this month south of the equator this month adding to the celestial show.

During this period the moon reaches its full phase on Tuesday February 7th. At that time the moon will be located opposite the sun in the sky and will remain above the horizon all night long. This weekend the waxing gibbous moon will be in the sky most of the night. There will be a little time between moon set and the start of morning twilight when dark skies will allow good observing conditions. The estimated total hourly rates for evening observers this week is near one for observers in the northern hemisphere and two for those south of the equator. For morning observers the estimated total hourly rates should be near four as seen from mid-northern latitudes and eight 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. Rates are reduced this week 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 February 4/5. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The list below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning. Detailed descriptions of each shower will be continued next week when lunar interference will be less severe.

Antihelion (ANT) – 09:56 (149) +11   Velocity 30km/sec
Northern Hemisphere – 1 per hr Southern Hemisphere – 1 per hour

Alpha Centaurids (ACE)  13:46 (206) -58   Velocity 57km/sec
Northern Hemisphere – <1 per hr Southern Hemisphere – 1 per hour

Pi Hydrids (PIH)   14:09 (212) -21   Velocity 70km/sec
Northern Hemisphere – <1 per hr Southern Hemisphere – <1 per hour

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

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