Comet Section        




Lovejoy continues to be the comet of the moment as it refuses to fade away. Short-period comet 15P/Finlay is now fading but is being replaced by brightening 88P/Howell.

Evening Comets

C/2014 Q2 (Lovejoy) [Perihelion on 2015-Jan-30 at 1.29 AU from the Sun]

Recent observations show C/2014 Q2 (Lovejoy) to be an easy binocular object at magnitude ~5.8. Though it is over 2 months after perihelion, the comet continues to become more active. This month it moves away from both the Sun (1.37 to 1.49 AU) and Earth (1.31 to 1.63 AU) and should rapidly fade. But if its current brightness trend continues it may not fade much at all. All bets are off as to what this surprising comet has in store for us. By the end of March it could be anywhere from 6th to 8th magnitude as its moves through Cassiopeia in the evening sky

The plot below shows a lightcurve of C/2014 Q2 produced from visual and CCD magnitude measurements submitted to the Section.

Recent ALPO images and observations of C/2014 Q2 (Lovejoy) can be found in the Comet Section Image Gallery and Magnitude Database. Finder charts can be found at the ALPO Comet Finder Chart page.

15P/Finlay [Perihelion on 2014-Dec-27 at 0.98 AU from the Sun]

Comet Finlay has had quite the apparition with two multi-magnitude outbursts. The comet’s last outburst was in January and since then it has settled down as it moves away from the Sun (1.33 to 1.51 AU) and Earth (1.66 to 1.92 AU). It peaked around 7th to 8th magnitude in January but is now a much fainter 12th magnitude and fading as it moves through Aries (Mar 1-26) and Taurus (Mar 26-31).

Recent ALPO images and observations of 15P/Finlay can be found in the Comet Section Image Gallery and Magnitude Database. Finder charts can be found at the ALPO Comet Finder Chart page.

Morning Comets

88P/Howell [Perihelion on 2015-Apr-06 at 1.36 AU from the Sun]

Comet Howell is a short-period comet completing a circuit around the Sun every 5.5 years. The comet was first imaged in 1955 though those observations went unrecognized until the comet was discovered by Ellen Howell in 1981. Its 2015 return marks its 8th observed apparition. During its last return in 2009, Howell peaked at 8th magnitude which was 1-2 magnitudes brighter than usual for this comet. If it behaves as it did in 2009 it will reach ~8th-9th magnitude this April/May. As of early March, Howell was around magnitude 10.5. It is a morning object moving through Sagittarius (Mar 1-6), Capricornus (Mar 6-31).

Recent ALPO images and observations of 88P/Howell can be found in the Comet Section Image Gallery and Magnitude Database. Finder charts can be found at the ALPO Comet Finder Chart page.

New Discoveries

Since the last update 8 new comets have been discovered. Most are faint and will remain so though two were found surprisingly close to the Sun.

C/2015 B2 (PANSTARRS) was found at 19th magnitude and may peak around 16th magnitude (perihelion at 3.37 AU in May 2016).

P/2015 C1 (TOTAS-Gibbs) is a short-period comet on a 17 year orbit. Its current 18th magnitude is about as bright as it will get. Perihelion will occur in May 2015 at 2.89 AU. It was co-discovered by the Teide Observatory Tenerife Asteroid Survey (TOTAS) and Alex Gibbs of the Catalina/Lemmon Sky Survey.

C/2015 C2 (SWAN) was first noticed by Rob Matson (Newport Coast, CA, USA) in publicly available data taken by the SWAN instrument on the SOHO spacecraft starting February 15. M. Mattiazzo (Swan Hill, Victoria, Australia) and V. Bezugly (Dnepropetrovsk, Ukraine) also independently discovered the comet in SWAN data. Ground-based observers were able to image the intrinsically faint comet at around 12th magnitude. The comet is a very difficult evening object at a small elongation of only 25 degrees and will remain at small elongations until May when it will be much fainter. Comet SWAN appears to have a ~200 year period and passed perihelion back on March 4 at 0.71 AU from the Sun.

C/2015 D1 (SOHO) is another small perihelion distance comet discovered in publicly available SOHO data. This time Worachate Boonplod used the LASCO C3 instrument to find the comet on February 18 at ~10th magnitude. As it passed its February 19th perihelion at a very close 0.02 AU from the Sun, the comet experienced a few flare-ups to as bright as magnitude 1. As the comet was leaving the C3 field-of-view the coma of the comet started to lose definition and ’smear’ out, the tell-tale signs of a comet undergoing nucleus disruption. When the comet was far enough from the Sun for ground-based observers only a low surface brightness ghost of a comet remained with no evidence of a surviving nucleus. As of March 10, CCD observers have been able to observe the remains of comet SOHO about 1/2 degrees to the NE of its predicted position. A few large aperture visual observers have been able to barely detect the comet as well.

C/2015 D2 (PANSTARRS) was already ~1.5 years past perihelion (2013-Oct-06 at 5.61 AU) when found by the Pan-STARRS project on Feb. 18 at 20th magnitude. It takes ~46 years to orbit the Sun and will only be getting fainter this return.

C/2015 D3 (PANSTARRS) was found a day after C/2015 D2. It is a long-period comet with a distant perihelion of 8.04 AU (2016-Jun-10). It won’t get much brighter than its current 19th magnitude.

C/2015 D4 (Borisov) was found by Gennady Borisov (Nauchnij, Crimea) with a CCD-equipped 0.3-m f/1.5 astrograph on Feb. 23 at 16th magnitude. Surprisingly, the comet was at perihelion last Halloween at a small distance of 0.81 AU from the Sun. At that time the comet was observable (though at a small elongation) from the Southern Hemisphere. Either the comet was missed or it never became bright enough for visual observers.

C/2015 D5 (Kowalski) was found by Richard Kowalski of the Catalina Sky Survey with the 1.5-m Mount Lemmon Survey telescopeon February 27 . Discovered at 19th magnitude it may brighten to 14th magnitude around the time of its 2015-Jun-15 perihelion at 2.27 AU.

As always, the Comet Section is happy to receive all comet observations, whether images, drawings or magnitude estimates.

- Carl Hergenrother (ALPO Comet Section Coordinator)

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