Meteor Activity Outlook for February 16-22, 2013

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 earth-grazer 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 first quarter phase on Sunday February 17th. At this time the moon is located ninety degrees east of the sun and sets near midnight local standard time (LST) as seen from mid-northern latitudes. As the week progresses the waxing gibbous moon will set during the early morning hours, allowing a few hours of dark skies between the time of moon set and the beginning of morning twilight. The estimated total hourly meteor rates for evening observers this week is near two as seen from the northern hemisphere and four as seen from south of the equator. For morning observers the estimated total hourly rates should be near eight from the mid-northern hemisphere and seventeen from the mid-southern hemisphere. 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. Evening 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 February 16/17. 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 Anthelion (ANT) radiant is currently centered at 10:44 (161) +07. This position lies in southern Leo, ten degrees southeast of the first magnitude star Regulus (Alpha Leonis). These meteors may be seen all night long but the radiant is best placed near 0100 LST when it lies on the meridian and is highest in the sky. Rates at this time should be near one per hour no matter your location. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of slow velocity.

The Alpha Centaurids (ACE) are active from a radiant located at 14:43 (221) -62. This position lies in southeastern Centaurus, very close to the position occupied by the zero magnitude star Rigel Kentaurus (Alpha Centauri). These meteors cannot be seen north of the northern tropical regions. They are best seen from mid-southern latitudes where the radiant lies high in the sky near 0500 local summer time. This shower peaked on February 8th so current rates would be near one per hour as seen from the southern hemisphere. At 56km/sec. the Alpha Centaurids would produce mostly swift meteors.

The Beta Herculids are active through Tuesday from a radiant located at 15:52 (238) +28. This position is actually located in Corona Borealis, four degrees northeast of the second magnitude star Alphecca (Alpha Coronae Borealis). It is suggested that the observer be liberal with shower association as the actual radiant position is not well defined. These meteors are best seen near during the last dark hour before dawn when the radiant lies highest above the horizon in a dark sky. Rates would mostly likely be less than one shower member per hour, no matter your location. Observers in the northern hemisphere have an advantage in that the radiant lies higher in the sky during the morning hours. At 56 km/sec. the Beta Herculids would produce mostly swift meteors.

The IMO video list of radiants has several entries for the Delta Serpentids (DSE). On most nights of possible activity this shower is extremely weak, far less than the weak sporadic rate seen this time of year from the northern hemisphere. On the morning of the February 16th though, it becomes the second most active radiant in the sky. At that time the radiant is located at 16:37 (249) +09, which actually places it in among the stars of Ophiuchus. The nearest bright stars are fourth magnitude Kappa and Iota Ophiuchi, which lie six degrees to the east. This position is well seen from either side of the equator. These meteors are best seen near during the last dark hour before dawn when the radiant lies highest above the horizon in a dark sky. On other mornings rates for this shower are so weak that the chance of sporadic alignment is extremely high. At 57 km/sec. the Delta Serpentids would produce mostly swift meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately six 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 fourteen 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. Rates are reduced during the evening hours 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 .

Anthelions (ANT) – 10:44 (161) +07   Velocity – 30km/sec.
Northern Hemisphere – 1 per hr.   Southern Hemisphere – 1 per hr

Alpha Centaurids (ACE) – 14:43 (221) -62   Velocity – 56km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – 1 per hr

Beta Herculids (BHE) – 15:52 (238) +28   Velocity – 56km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr

Delta Serpentids (DSE) – 16:37 (249) +09   Velocity – 57km/sec.
Northern Hemisphere – 1 per hr.   Southern Hemisphere – 1 per hr

Clear Skies!
Robert Lunsford
American Meteor Society

Awesome Fireball Event in central Russia

2012 DA14 may not be on a collision course with Earth later today but a smaller asteroid was. A major fireball (and most likely also a meteorite dropping event) occurred over the city of Chelyabinsk, Russia. Chelyabinsk is a city of 1+ million people located just to the East of the Ural Mountains and just north of the Russia-Kazakhstan border.

The fireball that occurred there this morning appeared brighter than the Sun and produced a sonic boom that shattered windows causing flying glass-induced injuries to hundreds of people. A large building in town also seems to have been damaged. Though it is still uncertain if this was due to a large meteorite or the sonic boom.

An event like this happening only hours before the close flyby of the ~45-meter in diameter asteroid 2012 DA14, begs the question of whether the two are linked. It is probably unlikely that the Chelyabinsk fireball and 2012 DA14 are related. Luckily there are so many great videos of the fireball that an accurate orbit for the asteroid that caused the fireball should be easily determined.

[Update: 2012 DA14 and the Russian fireball can not be related. The radiant (the region of the sky that a DA14 or a piece of DA14 would appear to come from) of DA14 is at the very far southern declination of -81 degrees. This is the reason why DA14 is only visible from the southern hemisphere as it approaches Earth. A radiant that far south could not produce a fireball over Russia which is in the northern hemisphere. Any pieces of DA14 would only be able to impact Earth over the southern hemisphere or a few degrees north of the Equator. The fact that the Russian fireball and the 2012 DA14 close approach are happening on the same day is just a coincidence.]

Up-to-date information can be found at RT, here and here, and RMNB.

Many videos have been posted. The first 2 show the fireball itself. The last 2 are videos of the resulting contrail. What is very impressive about the last two is that the videos also caught the sonic boom. In one of the videos you can hear glass shattering in the background. Simply awesome…

2012 DA14

Remember to duck this Friday!

As any one who has been following the news lately knows, a small asteroid named 2012 DA14 will make an especially close flyby of Earth later this week. The 50-meter wide (~150-foot) asteroid will pass within 27,700 km (22,200 miles) of the Earth’s surface at 19:24 UT on February 15. At that time the asteroid will be over the Indian Ocean.

This is the closest known approach of an asteroid of this size. Such an occurrence should happen once every 40 years, on average. The reason this is the first detected close approach of its kind is because we only possessed the technology to easily discover such object over the past 10-15 years.

There is a zero probability that this object will hit the Earth this week. Its orbit is well enough known that not only will it not hit the Earth but it will also not be impacting any Earth-orbiting satellites. There is a 1-in-50,000 chance DA14 could hit the Earth in the years between 2080 and 2109, though it is likely that even these small impact probabilities will drop to zero after this week’s flyby.

More on the close approach of 2012 DA14 can be found at NASA/JPL and Sky & Telescope.

As close as this asteroid gets to Earth, it small size means it never gets very bright. It will brighten to about 7-8th magnitude at its closest which will make it an easy binocular or small telescope object. The hard part will be finding it. It will be moving as fast as nearly a degree per minute at its fastest. Not too mention being so close also means parallax will be an issue.

By the time the sun sets in the United States, it will have faded to 11th-12th magnitude. Only observers with relatively large telescopes will be able to spot DA14 by then as it recedes into the distance near the north star, Polaris.

Meteor Activity Outlook for February 9-15, 2013

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 earth-grazer 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 new phase on Sunday February 10th. At this time the moon is located near the sun and is invisible at night. As the week progresses the waxing crescent moon will enter the evening sky but will not interfere with meteor observing. The estimated total hourly meteor rates for evening observers this week is near three as seen from the northern hemisphere and five as seen from south of the equator. For morning observers the estimated total hourly rates should be near nine from the mid-northern hemisphere and eighteen from the mid-southern hemisphere. 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 February 9/10. 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 Anthelion (ANT) radiant is currently centered at 10:16 (154) +09. This position lies in southwestern Leo, three degrees southeast of the first magnitude star Regulus (Alpha Leonis). These meteors may be seen all night long but the radiant is best placed near 0100 LST when it lies on the meridian and is highest in the sky. Rates at this time should be near two per hour as seen from the northern hemisphere and one per hour from south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of slow velocity.

The Alpha Centaurids (ACE) are active from a radiant located at 14:10 (212) -60. This position lies in southeastern Centaurus, very close to the position occupied by the first magnitude star Hadar (Beta Centauri). These meteors cannot be seen north of the northern tropical regions. They are best seen from mid-southern latitudes where the radiant lies high in the sky near 0500 local summer time. This shower peaked on February 8th so current rates would be near three per hour as seen from the southern hemisphere. At 56km/sec. the Alpha Centaurids would produce mostly swift meteors.

Activity from the Beta Herculids begins on Wednesday morning February 13th. This also happens to be the morning of maximum activity. This shower was discovered by Juergen Rendtel and Sirko Molau using data from the IMO video database. This shower is active from the 13th through the 19th. On the 13th the radiant is located at 16:27 (247) +24. This position is located in western Hercules, three degrees north of the third magnitude star Kornephoros (Beta Herculis). These meteors are best seen near during the last dark hour before dawn when the radiant lies highest above the horizon in a dark sky. Rates would mostly likely be less than one shower member per hour, no matter your location. At 56 km/sec. the Beta Herculids would produce mostly swift meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately seven 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 fourteen per hour as seen from rural observing sites and four 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 .

Anthelions (ANT) – 10:16 (154) +09   Velocity – 30km/sec.
Northern Hemisphere – 2 per hr.   Southern Hemisphere – 1 per hr

Alpha Centaurids (ACE) – 14:10 (212) -60   Velocity – 56km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – 3 per hr

Beta Herculids (BHE) – 16:27 (247) +24  Velocity – 56km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr

Clear Skies!
Robert Lunsford
American Meteor Society

Meteor Activity Outlook for February 2-8, 2013

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 earth-grazer 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 last quarter phase on Sunday February 3rd. At this time the moon is located ninety degrees west of the sun. The half illuminated moon will rise near midnight local standard time and will remain in the sky the remainder of the night. While producing much less light than a full moon, the last quarter moon will still hamper meteor observations during the morning hours. If your skies are transparent meteor observers can simply face the opposite direction of the moon and still carry on successful observations. As the week progresses the moon will less of a problem as the phase wanes and it rises later in the morning with each passing night. The estimated total hourly meteor rates for evening observers this week is near three no matter your location. For morning observers the estimated total hourly rates should be near seven from the mid-northern hemisphere and ten from the mid-southern hemisphere. 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. Morning rates are reduced 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 2/3. 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 Anthelion (ANT) radiant is currently centered at 09:48 (147) +11. This position lies in western Leo, four degrees west of the first magnitude star Regulus (Alpha Leonis). These meteors may be seen all night long but the radiant is best placed near 0100 LST when it lies on the meridian and is highest in the sky. Rates at this time should be near two per hour as seen from the northern hemisphere and one per hour from south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of slow velocity.

The Alpha Centaurids (ACE) are now active from a radiant located at 13:36 (204) -58. This position lies in southeastern Centaurus, five degrees northwest of the first magnitude star Hadar (Beta Centauri). These meteors cannot be seen north of the northern tropical regions. They are best seen from mid-southern latitudes where the radiant lies high in the sky near 0500 local summer time. As seen from the southern hemisphere rates will be rising this week and will peak on February 8th, when they should be near five per hour during the morning hours. At 56km/sec. the Alpha Centaurids would produce mostly swift meteors.

IMO Shower #22 is a weak unnamed shower active from January 29 through February 9. Peak activity occurs on February 8th from a radiant located at 13:42 (206) +09. This position is located in extreme southwestern Bootes, ten degrees southwest of the zero magnitude star Arcturus (Alpha Bootis). These meteors are best seen near 0400 LST, when the radiant lies highest above the horizon in a dark sky. Rates would mostly likely be less than one shower member per hour, no matter your location.  At 65 km/sec. IMO Shower #22 would produce mostly swift meteors. It is possible that these meteors are a continuation of the Coma Berenicids which were active In December and January.

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 seven 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. Morning rates are reduced this week 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 .

Anthelions (ANT) – 09:48 (147) +11   Velocity – 30km/sec.
Northern Hemisphere – 2 per hr.   Southern Hemisphere – 1 per hr

Alpha Centaurids (ACE) – 13:36 (204) -58   Velocity – 56km/sec.
Northern Hemisphere – <1 per hr. Southern Hemisphere – 2 per hr

IMO #22- 13:42 (206) +09   Velocity – 65km/sec.
Northern Hemisphere – <1 per hr. Southern Hemisphere – <1 per hr

Clear Skies!
Robert Lunsford
American Meteor Society

In the Transient Sky – February 2013

February 2013 Highlights
* Not one but two comets should be naked eye brightness for SH observers (C/2011 L4 and C/2012 F6)
* Up north only comets 273P/Pons-Gambart and C/2012 T5 are bright enough for small scopes at 9th magnitude
* Comet C/2011 F1 (LINEAR) is also in range of small telescopes from the SH
* Small near-Earth asteroid 2012 DA14 passes 34,000 km from Earth on the 16th
* Mercury and Mars pass within 1/2° of each other low in the WSW evening sky on the 7th
* The Moon joins Mercury and Mars on the evenings of the 10th and 11th
* Moon occults Jupiter for observers in southern Australia
* Saturn rises before midnight
* Jupiter continues to dominate 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>.

Planets

Evening Planets

Mercury –Mercury will have three good evening apparitions for Northern Hemisphere observers this year. The first takes place this month. The innermost planet is a relatively bright -1 magnitude at the start of the month. Though it slowly fades every night it rapidly ascends higher nightly in the western sky during dusk. On the 7th it passes ~0.4° from much fainter Mars. A very thin crescent Moon is located to the lower right of the duo on the evening of the 10th and to the upper right on the 11th. By the second half of the month Mercury is fading to 1st-2nd magnitude and falling back into the twilight glow.

Mars – Use Mercury and the Moon (see above) to spot Mars this month. The red planet will be all but unobservable for most observers for the next few months as it passes behind the Sun.

Jupiter – The King of the Planets dominates the evening sky being visible nearly overhead at the end of evening twilight. Jupiter is now two months past opposition. It spends the month just north of the stars of the Hyades cluster in Taurus as it fades from magnitude -2.5 to -2.3.  The Moon pays Jupiter a visit on the evenings of the 17th and 18th.

Morning Planets

Saturn – Saturn is an early morning object rising around 1:00 am at the start of the month and 11pm by the end of the month.  All month Saturn glows at magnitude +0.5 between Virgo and Libra. The Moon passes close to Saturn on the morning of the 3rd.

Venus – Venus is too close to the Sun for easy observation this month. It will be back, this time in the evening sky, this summer.

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. Meteor activity is still near an annual maximum this month.

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 February mornings, 5 or so Sporadic meteors can be observed per hour from a dark moonless sky. The rate is near an annual minimum this month.

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)

C/2011 L4 (PANSTARRS)

Last month Comet PANSTARRS looked on pace to peak around magnitude -1 near its March 10th perihelion. But over the past few weeks the comet has not been brightening as quickly as hoped. As a result it is likely that the comet will be much fainter than -1 at its peak brightness and more along the lines of 2nd to 4th magnitude. The comet will still be a nice sight especially in binoculars and telescopes.

The comet was first seen by the Hawaiian based PanSTARRS asteroid survey on June 6, 2011 at a large distance of 7.9 AU from the Sun. At perihelion it will approach within 0.30 AU of the Sun. The comet is a new Oort cloud comet meaning it is making its first passage through the inner Solar System. The fact that it is a new Oort cloud comet explains its failure to brighten as quickly as first predicted. These sort of comet often appear relatively bright when far from the Sun because they still contain a large amount of very volatile ices. As the comet approaches the Sun, these ices sublimate and the comet brightens at a slower rate.

This month, the comet starts at a distance of 1.0 AU from the Sun with that distance dropping to 0.43 AU at the end of the month. A few recent observations place it at magnitude ~6.5-7.0. If it continues to brighten at its current rate it should become a naked eye object by mid-month. The comet will only be observable from the Southern Hemisphere this month as moves from the constellation of Sagittarius to Piscis Austrinus. Northern observers will have to wait till late March when the comet should be a naked eye object.

Finder charts can be found at Chasing Comets.

Ephemeris for C/2011 L4 (PANSTARRS)
Date            RA        DEC    Delta   r   Elong    V
2013 Feb 01   19h 21m  -45d 22'  1.649 1.009   34    6.8
2013 Feb 10   20h 26m  -45d 15'  1.427 0.822   34    6.0
2013 Feb 19   21h 49m  -41d 06'  1.238 0.626   30    4.5
2013 Feb 28   23h 16m  -29d 13'  1.118 0.431   22    3.0

RA = Right Ascension, DEC = Declination, Delta = distance from Earth in AU
r = distance from the Sun in AU, Elong = elongation from Sun in degrees
V = Visual magnitude

C/2012 F6 (Lemmon)

Everyone was expecting C/2011 L4 (PANSTARRS) and C/2012 S1 (ISON) to be the two naked eye comets of 2013. No one was expecting C/2012 F6 (Lemmon) to be vying for the status of naked eye comet when it was discovered by Alex Gibbs of the Mount Lemmon survey back on March 23, 2012. At that time the comet was a faint 20th-21st magnitude and 5.0 AU from the Sun. It also appeared to be an intrinsically faint comet. So faint in fact that I though it had a good chance of disintegrating near perihelion. Instead the comet has brightened at a rapid rate. If this brightening trend continues the comet may be a fine naked eye object this February through May. Perihelion will occur on March 24, 2013 at a distance of 0.73 AU from the Sun.

Over the past few days visual observers have estimated the comet at magnitude 6.2 to 6.5.

The comet is already too far south for most northern observers and the comet will continue to travel deeper into the southern sky this month. As a result, this comet will only be visible to southern observers till May.

The comet starts the month around magnitude 6.3 and will continue to rapidly brighten all month. By the end of the month the comet may be as bright as magnitude 6.0. It will be traveling through the far southern constellations of Musca, Octans, Tucana and Phoenix.

Finder charts can be found at Chasing Comets.

Ephemeris for C/2012 F6 (Lemmon)
Date            RA        DEC    Delta   r   Elong    V
2013 Feb 01   13h 32m  -81d 08'  0.993 1.221   76    6.3
2013 Feb 10   23h 00m  -81d 07'  0.993 1.098   67    5.5
2013 Feb 19   23h 52m  -65d 58'  1.053 0.981   57    4.5
2013 Feb 28   00h 03m  -52d 43'  1.154 0.877   47    4.0

RA = Right Ascension, DEC = Declination, Delta = distance from Earth in AU
r = distance from the Sun in AU, Elong = elongation from Sun in degrees
V = Visual magnitude

Binocular Comets (V = 6.0 – 8.0)

None

Small Telescope Comets (V = 8.0 – 10.0)

Comet C/2012 T5 (Bressi)

Comet Bressi was first spotted by Spacewatch observer Terry Bressi from Kitt Peak on October 14, 2012. If any of the comets in this blog post are likely to not survive perihelion, this is the one.

The comet is currently just within 1 AU of the Sun and little over 1 AU from Earth. Even after a recent outburst a week or two ago the comet is still rather faint. My observations place it at V magnitude 13.0 but this is most likely an underestimate as the observations were hampered by a very right Moon nearby and the comet’s low elevation. Visual observers place it closer to magnitude 11-12.

Comet Bressi will reach perihelion on February 24 at a distance of 0.32 AU from the Sun. It will be interesting to see if it survives. If it does it may brighten enough to be seen in small telescopes though observations will be limited to southern observers until March.

Recent observations place the comet at magnitude 10.5. If it can hold together till perihelion it should can brighten up to 8th-9th magnitude. Northern observers will only be able to follow the comet till around mid-month. After that it will solely be a southern object till next month.

Finder charts can be found at Chasing Comets.

Ephemeris for C/2012 T5 (Bressi)
Date            RA        DEC    Delta   r   Elong    V
2013 Feb 01   23h 51m  -30d 29'  1.016 0.709   41   10.5
2013 Feb 10   23h 20m  -33d 04'  0.984 0.517   30    9.8
2013 Feb 19   22h 28m  -32d 03'  0.933 0.357   21    8.9
2013 Feb 28   21h 34m  -19d 22'  0.917 0.344   20    8.0 or Puff!

RA = Right Ascension, DEC = Declination, Delta = distance from Earth in AU
r = distance from the Sun in AU, Elong = elongation from Sun in degrees
V = Visual magnitude

273P (Pons-Gambart)

On June 21, 1827, French astronomers Jean Louis Pons and Jean-Félix Adolphe Gambart discovered a comet among the stars of Cassiopeia. Both men were prolific comet finders. Pons was the most prolific discoverer of comets up until the modern era and still holds the record for most visual discoveries. A record that is unlikely to ever be broken. Between 1801 and 1827, Pons found 26 comets. Comet Pons-Gambart was his second to last comet find. Though not as prolific as Pons, Gambart is credited with 5 comet discoveries between 1822 and 1834. Comet Pons-Gambart was his 3rd find.

As the comet was already a few weeks past perihelion at discovery, it was only observed for ~1 month before it faded. Over the years, orbit computers have noticed that Pons-Gambart was on an obvious elliptical orbit and determined periods between ~45 and 65 years. The only problem was with periods that short the comet should have returned at least 2 to 4 times since 1827. Perhaps the comet was fainter now or even broke up in the intervening years to explain why it was constantly being missed.

Fast forward to this year… Robert Matson of Newport Coast, CA found evidence of an unknown comet on images taken with the SOHO spacecraft. SOHO’s SWAN imager is used to map the Lyman-α emission of the solar wind. SWAN is also very good at detecting hydrogen was dissociated water molecules released by comets. As a result, SWAN has been used to discover comets. Matson noted the presence of a comet on SWAN images from Nov. 7, 10, 11, 13 and 19. He then informed a number of observers about the new find and on Nov. 29 Terry Lovejoy of Australia found the comet.

Before the comet was even formally announed, Maik Meyer of Limburg, Germany noticed the similarities between the new SWAN/Matson comet and long-lost Comet Pons-Gambart. There is little doubt that the two are related and are probably the same object. Only problem is the 2012 observations don’t exactly match the 1827 observations assuming orbital periods of 45-65 years. A recent MPEC released by Gareth Williams of the Minor Planet Center found that the 2012 observations are consistent with a much longer period than previously assumed. It is likely that Pons-Gambart wasn’t really missed before because with a 188 year orbit this is actually its first return since 1827.

At first there was still come question as to whether the newly seen comet was Pons-Gambart and for awhile the comet was only known by its designation C/2012 V4. The Minor Planet Center has now officially announced it as 273P/Pons-Gambart.

After spending over a month too close to the Sun for observation, 273P is once again observable. This month it is a morning object traveling north from Serpens Cauda into Hercules.

Finder charts can be found at Chasing Comets.

Ephemeris for 273P/Pons-Gambart
Date            RA        DEC    Delta   r   Elong    V
2013 Feb 01   18h 30m  +05d 10'  1.636 1.132   42    9.0
2013 Feb 10   18h 22m  +10d 30'  1.538 1.243   53    9.2
2013 Feb 19   18h 10m  +16d 46'  1.432 1.359   65    9.4
2013 Feb 28   17h 54m  +24d 10'  1.331 1.477   77    9.7

RA = Right Ascension, DEC = Declination, Delta = distance from Earth in AU
r = distance from the Sun in AU, Elong = elongation from Sun in degrees
V = Visual magnitude

C/2011 F1 (LINEAR)

No one has seen this comet for a few months because it has been too close to the Sun. It should be around magnitude 9-9.5 as it slowly moves away from the Sun.

The LINEAR near-Earth asteroid survey picked up this comet back on March 17, 2011 at 18th magnitude. It passed perihelion on January 8 of this year at 1.82 AU from the Sun.

It is yet another comet that can only be seen from the Southern Hemisphere this month as it moves from Sagittarius to Microscopium.

Finder charts can be found at Chasing Comets.

Ephemeris for C/2011 F1 (LINEAR)
Date            RA        DEC    Delta   r   Elong    V
2013 Feb 01   19h 45m  -36d 01'  2.691 1.845   24    9.2
2013 Feb 10   20h 13m  -37d 51'  2.662 1.867   29    9.3
2013 Feb 19   20h 44m  -39d 26'  2.634 1.896   33    9.4
2013 Feb 28   21h 15m  -40d 44'  2.610 1.931   38    9.5

RA = Right Ascension, DEC = Declination, Delta = distance from Earth in AU
r = distance from the Sun in AU, Elong = elongation from Sun in degrees
V = Visual magnitude

Asteroids

2012 DA14

On February 15th a ~50-meter asteroid will pass 34,000 km or 21,000 miles from Earth. The asteroid will appear as a fast moving star of 8th magnitude at its closest. For observers in the United States, the asteroid will already have made its closest approach when it becomes visible. As a result it will have faded to 11th magnitude by then.

I’ll post more on this object over the next week or so.