Comet Section        

 
 

ALPO COMET SECTION NEWS FOR JULY 2015

2015-July-06

July sees one of the brightest comets of the year reach perihelion. C/2014 Q1 (PANSTARRS) may be a nice binocular object for observers south of the Equator as it climbs into darker skies later this month. Northern observers are in a bit of a summer drought as no comets brighter than 9th magnitude will be visible.

Evening Comets

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

Lovejoy is located in the far northern sky as it slowly moves south through Ursa Minor (July 1-16) and Draco (16-31). Now 5 months past perihelion, the comet is still around magnitude 9.0-9.5.  Its distance from the Sun (2.48 to 2.81 AU) and Earth (2.52 to 2.83 AU) continues to increase resulting in a slow fade to magnitude 9.7 to 10.2 by the end of July.

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.

C/2015 G2 (MASTER) [Perihelion on 2015-May-23 at 0.78 AU from the Sun]

Comet MASTER peaked at magnitude 6.0 in mid-May. As of late June it had faded to 9.0 and will continue to fade in July. Unfortunately it is very close to the Sun at the start of the month (elongation 25°) and only gets closer as the month progresses. It will be lost in the glare of the Sun till September when it will be fainter than 11th-12th magnitude.

Recent ALPO images and observations of C/2015 G2 (MASTER) 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

C/2014 Q1 (PANSTARRS) [Perihelion on 2015-Jul-06 at 0.31 AU from the Sun]

Comet PANSTARRS reaches perihelion today (July 6) at a distance of 0.31 AU from the Sun. Unfortunately it is also 1.25 AU from Earth and only 10° elongation from the Sun. As a result, very few observers have been able to observe Q1 over the past few weeks. What we do know is that is appears to be around 4th magnitude. Northern observers are out of luck this month. Southern hemisphere observers will be able to pick the comet up towards the end of the month as it moves away from the glare of the Sun. By then the comet will be rapidly fading to 6th-8th magnitude as it moves through Auriga (July 1), Gemini (1-8), Cancer (8-18), Leo (18-22), Sextans (22-31).

Recent ALPO images and observations of C/2014 Q1 (PANSTARRS) can be found in the Comet Section Image Galleryand Magnitude Database. Finder charts can be found at the ALPO Comet Finder Chart page.

C/2013 US10 (Catalina) [Perihelion on 2015-Nov-15 at 0.82 AU from the Sun]

C/2013 US10 is inbound towards a November perihelion. Currently around 10th magnitude, Comet Catalina is well place for southern observers. Northern hemisphere observers are having an increasingly more difficult time observing the comet as it heads south through Sculptor (July 1-5), Phoenix (5-23), Grus (23-24) and Tucana (24-31). Catalina starts the month at 2.38 AU from the Sun and 1.81 AU from Earth and ends the month at 1.97 AU and 1.16 AU from the Sun and Earth, respectively.

Recent ALPO images and observations of C/2013 US10 (Catalina) can be found in the Comet Section Image Galleryand Magnitude Database. Finder charts can be found at the ALPO Comet Finder Chart page.

New Discoveries

Pan-STARRS lead the way in June with 3 new discoveries.

C/2015 K5 (PANSTARRS) is a short-period comet with a period of 17 years. Perihelion occurred on June 6 at 2.99 AU. Discovered by Pan-STARRS on May 29, it was already as bright as it’ll get at 20th magnitude.

C/2015 LC2 (PANSTARRS) is another faint Pan-STARRS find. The survey picked it up at its brightest (~19th magnitude) on June 7. Perihelion was in April at a distance of 5.88 AU. C/2015 LC2 is a long-period comet.

C/2015 M1 (PANSTARRS) is yet another faint Pan-STARRS long-period comet. It peaks at 19th magnitude and is already past its May 16th perihelion at 2.10 AU from the Sun.

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

- Carl Hergenrother (Acting ALPO Comet Section Coordinator)

 
 

ALPO COMET SECTION NEWS FOR JUNE 2015

2015-June-04

May was a bit of a slow month for the Comet Section. The brightest comet of the month, C/2015 G2 (MASTER), was only observable from the southern hemisphere (where our sole southern hemisphere visual observer, Willian Souza, has been following it). The second brightest comet, C/2014 Q2 (Lovejoy), was only seen by northern observers. Though Lovejoy is still around 8th magnitude, reported observations of this comet have fallen off. Perhaps we are all experiencing some Lovejoy fatigue after 8 months of observation (I know I only ventured outside once this month to observe Lovejoy).

June is a transitional month as we watch Lovejoy and MASTER fade and await the next two potentially bright objects. Unfortunately theses upcoming objects, C/2013 US10 (Catalina) and C/2014 Q1 (PANSTARRS), will be difficult to observe especially for northerners.

Evening Comets

C/2015 G2 (MASTER) [Perihelion on 2015-May-23 at 0.78 AU from the Sun]

In the middle of May, Comet MASTER peaked at magnitude 6.0 for a few days around its May 13 perihelion, possible due to a small outburst. For much of May the comet was between magnitude 6.3 and 7.1. ALPO contributor Willian Souza of Brazil has submitted 10 magnitude estimates of MASTER. His latest estimate from May 29 shows the comet having already faded to magnitude 7.1 as it moves away from the Sun (0.79 to 1.06 AU) and Earth (0.93 to 1.88 AU).

MASTER will only be visible from the southern hemisphere this month as an evening object in Monoceros (Jun 1-7), Canis Minor (7-26) and Cancer (26-30). It will be lost in the glare of the Sun even for southern observers later in the month and won’t reappear till September. By then northern observers will also be able to observe it though it may have faded below 11th-12th magnitude by then.

Recent ALPO images and observations of C/2015 G2 (MASTER) can be found in the Comet Section Image Galleryand Magnitude Database. Finder charts can be found at the ALPO Comet Finder Chart page.

Morning Comets

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

Lovejoy is circumpolar for northern observers and will spend the whole month in Ursa Minor. Now 4 months past perihelion, the comet is still around magnitude 8.0-8.5.  Its distance from the Sun (1.86 to 2.18 AU) and Earth (2.09 to 2.31 AU) continues to increase.

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.

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

Comet Howell is now 2 months past perihelion as it recedes from the Sun (1.48 to 1.64 AU) and moves a bit closer to Earth (1.70 to 1.65 AU) . Recent observations place Howell at magnitude ~10.0 though it should fade by a magnitude or so during June. The comet can be seen in the morning sky as it moves through Cetus (Jun 1-11), Pisces (12-30).

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.

C/2014 Q1 (PANSTARRS) [Perihelion on 2015-Jul-06 at 0.31 AU from the Sun]

I wish we knew more about what this comet is up to. After discovery last August at a heliocentric distance of 4.9 AU, early predictions suggested PANSTARRS would peak at 2nd magnitude this summer. As is often the case with comets new to the inner Solar System, it brightened slowly and as of late May was only around magnitude 10-11. This suggests its peak brightness is more likely to be around magnitude 6.

Unfortunately, Q1 will be a difficult comet to observe. Northern observers are completely out of luck and will never get a good shot at the comet. Southern observers will have to wait till late July before it exits the glare of the Sun. This month Q1’s heliocentric distance decreases from 0.97 to 0.36 AU while its geocentric distance drops from 1.76 to 1.30 AU.

Recent ALPO images and observations of C/2014 Q1 (PANSTARRS) can be found in the Comet Section Image Gallery and Magnitude Database. Finder charts can be found at the ALPO Comet Finder Chart page.

C/2013 US10 (Catalina) [Perihelion on 2015-Nov-15 at 0.82 AU from the Sun]

Another inbound comet predicted to be bright this year is C/2013 US10 (Catalina). Located in Sculptor all month long, Catalina is well placed for southern observers but a difficult sight for northern watchers. The comet is currently between magnitude 11 and 12 and should continue to brighten as it approaches its November perihelion. It is still a rather distance 2.76 AU from the Sun at the start of the month and 2.38 AU at the end. Its distance from Earth drops from 2.68 to 1.82 AU.

Recent ALPO images and observations of C/2013 US10 (Catalina) 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

A new crop of discoveries were announced in May. As usual, PANSTARRS leads the way in discoveries.

C/2015 GX (PANSTARRS) was initially classified as an asteroid following its April 8th discovery by the Pan-STARRS 1.8-m telescope. Over a month later on May 9, Roberto Haver detected cometary activity with a 0.37-m telescope in Frasso Sabino, Italy. Additional observations show C/2015 GX to be a Halley-type periodic comet with a period of 65 years and perihelion on 2015 August 26 at 1.97 AU from the Sun. The comet was around 20th magnitude at discovery and shouldn’t get much brighter then 18th magnitude (though Halley-types have a habit of brightening rapidly near perihelion).

C/2015 H2 (PANSTARRS) was discovered on April 24. Perihelion will be at a distant 4.95 AU in September of 2016. Currently 19th magnitude, this PANSTARRS discovery may only brighten up to 17th magnitude or so.

C/2015 J1 (PANSTARRS) passed perihelion last July at 6.03 AU. When first seen on May 14 it was a faint 20th magnitude which is as bright as it should get.

C/2015 J2 (PANSTARRS) is similar to the last two comet finds. It is also a faint high-q long-period comet. Found on May 15 it will pass perihelion in September at 4.32 AU and shouldn’t get much brighter than its current 18-19th magnitude.

P/2015 J3 (NEOWISE) is a short-period comet with a period of 6.4 years and perihelion of 1.50 AU. Discovered by the NEOWISE program being conducted by the WISE IR spacecraft, NEOWISE is a faint comet that shouldn’t get brighter than 19th magnitude.

C/2015 K1 (MASTER) is the second discovery of 2015 by the “Mobile Astronomical System of the Telescope-Robots” project. Similar to C/2015 G2, K1 was found with one of their 0.4-m telescopes in South Africa. It passed perihelion back in October at 2.57 AU from the Sun when it should have been around 14th magnitude. Located deep in the southern sky it went unnoticed at the time. The comet is now 16-17th magnitude and fading.

C/2015 K2 (PANSTARRS) is a runt. Even though it will come reasonably close to the Sun at 1.46 AU on 2015-Jun-08 and was 0.56 AU from Earth when discovered on May 18, the comet is an extremely faint 20-21th magnitude.

C/2015 K4 (PANSTARRS) is a long-period comet discovered by PANSTARRS on May 24 at 18-19th magnitude. With perihelion already passed (2015-May-01 at 2.01 AU), the comet is as bright as it will get.

51P-D/Harrington is a piece of the main nucleus of comet 51P/Harrington which experienced splitting events in 1994 and 2001. Component D was observed to separate from 51P back in late 2001. Surprisingly, Pan-STARRS recovered component D on May 30 at 22nd magnitude. 51P-A (the primary) and 51P-D are separated by a little over half of a degree on the sky. 51P-A has recently been observed at 16th magnitude as it approaches its August perihelion at 1.70 AU from the Sun (when it’ll be 13th magnitude).

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

- Carl Hergenrother (Acting ALPO Comet Section Coordinator)

 
 

ALPO COMET SECTION NEWS FOR MAY 2015

2015-May-01

For the first time in months the brightest comet in the sky will not be C/2014 Q2 (Lovejoy). Sometime this month it should be surpassed by newly discovered C/2015 G2 (MASTER). Unfortunately for us up north, MASTER will only be visible from southern latitudes so Lovejoy will remain the best comet for northerners.

Visual and CCD magnitude measurements of comets C/2015 G2 (MASTER), C/2015 F5 (SWAN-Xingming), C/2015 F3 (SWAN), C/2015 F2 (Polonia), C/2014 Q2 (Lovejoy), C/2014 E2 (Jacques), C/2013 X1 (PANSTARRS), C/2013 US10 (Catalina) and 88P/Howell were submitted by Salvador Aguirre (3), Carl Hergenrother (15), John Sabia (1) and Willian Souza (3). We’ve also received CCD images of comets from Carl Hergenrother, Gianluca Masi, Frank Melillo and John Sabia.

Morning Comets

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

Lovejoy has been the brightest comet in the sky for the past ~6 months or so. As May begins, it is still a 7th magnitude object. It may still be as bright as 8th magnitude at the end of the month if its recent rate of fading continues. Its distance from the Sun (1.86 to 2.18 AU) and Earth (2.09 to 2.31 AU) continues to increase this month as its passes through the northern circumpolar sky in Cassiopeia (May 1), Cepheus (May 2-27) and Ursa Minor (May 27-31). On May 29 it passes within 1° of the north celestial pole.

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.

C/2015 G2 (MASTER) [Perihelion on 2015-May-23 at 0.78 AU from the Sun]

Recently discovered Comet MASTER was found on Apr 7 UT in data taken by the MASTER (Mobile Astronomical System of the Telescope-Robots) program with a 0.4-m f/2.5 telescope located at the South African Astronomical Observatory. At discovery, Comet MASTER was located very close to 9th magnitude comet 88P/Howell. ALPO observers have watched MASTER brighten from magnitude 8.8 on April 16th to 7.7 on the 29th. The comet should peak around magnitude 6.5 around the time of its closest approach to Earth on May 13 at 0.47 AU. The comet will have faded to around magnitude 7 by perihelion on May 23 at 0.78 AU.

MASTER will only be visible from the southern hemisphere or very low northern latitudes this month. It starts the month as a morning object but passes south of the Sun and enters the evening sky around mid-month as it travels through Sculptor (May 1-8), Fornax (8-13), Eridanus (13-15), Caelum (15-16), Lepus (16-21), Canis Major (21-25) and Monoceros (26-31). It will be lost in the glare of the Sun even for southern observers by late July and won’t reappear till September. By then northern observers will also be able to observe it though it may have faded below 11th-12th magnitude by then.

Recent ALPO images and observations of C/2015 G2 (MASTER) can be found in the Comet Section Image Gallery and Magnitude Database. Finder charts can be found at the ALPO Comet Finder Chart page.

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

Comet Howell passed perihelion last month at a distance of 1.36 AU from the Sun. Recent observations place Howell at magnitude 9.5 to 10.0 though it should fade by a magnitude or so during May. The comet can be seen in the morning sky as it moves through Aquarius (May 1-13), Pisces (13-25) and Cetus (25-31).

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 3 new comets have been discovered.

C/2015 F5 (SWAN-Xingming) was discussed in an April 11th Comet Section post. It is a shared discovery between SWAN data miners Szymon Liwo (Swidnica, Poland) and Worachate Boonplod (Samut Songkhram, Thailand)  and Xingming sky survey members Guoyou Sun and Xing Gao (XinJiang, China).

Perihelion occurred on March 28 at a small distance of 0.35 AU followed by closest approach to Earth on April 14 at 0.60 AU. The comet is currently fading fast from an observed peak brightness of 10th magnitude.

C/2015 G2 (MASTER) was described above.

C/2015 H1 (Bressi) was found by Terry Bressi with the Spacewatch 1.8-m telescope on Kitt Peak on April 20 UT. At discovery, Bressi was 18th magnitude. Perihelion occurred earlier in the month (Apr. 8) at a distance of 1.94 AU from the Sun. It should only get as bright as 17th magnitude.

Other Comet News

I forgot to mention in last month’s News that March discovery C/2015 F3 (SWAN) shares a similar orbit with C/1988 A1 (Liller) and C/1996 Q1 (Tabur). Liller was a nice comet during the winter and spring of 1988 when it reached 5th magnitude. Tabur also reached 5th magnitude but underwent a disruption event prior to perihelion and slowly disintegrated from sight. Surprisingly the ‘apparently’ fainter C/2015 F3 survived perihelion but recent images, like the one below by Comet Section contributor Gianluca Masi, show the comet slowly fading away. Whether this is due to a disruption of the nucleus or just normal (but rapid) fading due to an increasing heliocentric distance remains to be seen. Comet SWAN is currently located a few degrees from the north celestial pole in Camelopardalis. As the image shows, it is very diffuse and about 12-13th magnitude or fainter.

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

- Carl Hergenrother (Acting ALPO Comet Section Coordinator)

 
 

TWO NEW COMET DISCOVERIES

2015-April-11

The discovery of two new comets were announced yesterday. Both are bright enough for small telescope observers at ~10th magnitude.

C/2015 F5 (SWAN-Xingming) was discovered by a number of people in publicly available data from the SWAN instrument on the SOHO spacecraft. This is the third comet discovered in SWAN data this year. It became visible in the SWAN data on March 29 UT. According to the Central Bureau of Astronomical Telegrams, the first reports of the comet were received on April 4 UT from Szymon Liwo (Swidnica, Poland) and Worachate Boonplod (Samut Songkhram, Thailand). The next day the comet was independently discovered by Guoyou Sun and Xing Gao (XinJiang, China) on images taken with a 0.11-m f/5 refractor in the course of their Xingming sky survey. At the time of their discovery C/2015 F5 was only 22 degrees from the Sun!

Perihelion occurred on March 28 at a small distance of 0.35 AU. Closest approach to Earth will be on April 14 at 0.60 AU. The comet is currently only 10th magnitude and should rapidly fade as it moves away from the Earth and Sun. As of today (April 11), it is a morning object located in Andromeda at an elongation of only 25 degrees. Over the next few days it passes well north of the Sun and becomes an evening object as it moves through Andromeda (Apr 10-18), Perseus (18-24) and Auriga (24-30).

C/2015 G2 (MASTER)

The second recent discovery was found on Apr 7 UT on data taken by the MASTER (Mobile Astronomical System of the Telescope-Robots) program with a 0.4-m f/2.5 telescope located at the South African Astronomical Observatory. At discovery, Comet MASTER was located very close to 9th magnitude comet 88P/Howell. As a result, observers monitoring SWAN data could not differentiate between the new comet and 88P (SWAN’s resolution is very poor).

Comet MASTER is still inbound and will pass perihelion on 2015 May 23 at 0.78 AU. Closest approach to Earth is on May 13 at 0.47 AU. Currently 10th magnitude, it may brighten to ~6th magnitude at perihelion. Southern hemisphere observers will be able to follow the comet for the next few months. Unfortunately, northern observers will lose sight of the comet in the coming week or two.

The image below was taken on April 5 from the SOHO SWAN instrument. It shows 5 comets. The other objects in the image are from stellar/galactic sources that weren’t properly subtracted from the data. The coordinate system is in ecliptic coordinates with the Earth at 180,0 and Sun at 0,0.

- Carl Hergenrother (Comet Section)

 
 

ALPO COMET SECTION NEWS FOR APRIL 2015

2015-April-01

Easter occurs in April this year. So it is fitting that one of our brighter comets is doing an Energizer bunny impersonation. It just keeps going and going and going… C/2014 Q2 (Lovejoy) remains the brightest comet in the sky. Though it is 2+ months past perihelion it has only faded from ~4th to ~6th magnitude. Two other comets, 88P/Howell and C/2015 F3 (SWAN), are also bright enough for small aperture observers.

Special thanks to the observers who submitted comet magnitude estimates during March of comets C/2014 Q2 (Lovejoy) and 88P/Howell: Salvador Aguirre (18 estimates), Carl Hergenrother (6) and John D. Sabia (4); and CCD images of C/2013 A1 (Siding Spring) and Lovejoy: Gianluca Masi and Frank Melillo.

Evening Comets (actually both are circumpolar)

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

As mentioned above, Lovejoy has remained bright even with increasing heliocentric and geocentric distances. We knew at some point the comet’s fading trend would quicken and recent observations from the past 2 weeks do show a more rapid rate of fading. At the start of April, the comet is around magnitude 6.5 and if its current rate of fading continues it will be a tad fainter than magnitude 8.0 by the end of the month. It will move away from the Sun (1.58 to 1.85 AU) and Earth (1.78 to 2.08 AU) this month as its passes through the circumpolar sky in Cassiopeia.

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.

C/2015 F3 (SWAN) [Perihelion on 2015-Mar-09 at 0.83 AU from the Sun]

Comet SWAN is the second comet in 2015 to be discovered with the SWAN Lyman-α instrument on the SOHO spacecraft. Robert Matson (Newport Coast, CA, USA) first noticed the comet on SWAN data taken on March 5. V. Bezugly (Dnepropetrovsk, Ukraine) also made an independent discovery. Comet SWAN appeared to rapidly brighten in the SWAN data as it passed through its March 9th perihelion at 0.83 AU. By March 24th, ground-based observers were able to pick up the comet as it rapidly moved out of the Sun’s glare in the evening sky. The most recent observations show SWAN to be around magnitude 10.0. It is a dynamically old comet with an orbital period ~1200 years.

SWAN is racing towards the north as travels through Cassiopeia (Apr 1-13) and Cepheus (Apr 13-30). It passes within 4 degrees of the north celestial pole at the end of the month. There isn’t much photometry for this comet so its brightness trend is still uncertain but the comet should fade from 10th to 11th magnitude as its moves away from the Sun (0.93 to 1.26 AU) but closer to Earth (1.23 AU to 1.05 AU).

Morning Comets

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

Comet Howell reaches perihelion this month at a distance of 1.36 AU from the Sun. Recent observations place Howell at magnitude 9.5 to 10.0. The comet can be seen in the morning sky as it moves through Capricornus (Apr 1-6) and Aquarius (Apr 6-30).

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 4 new comets have been discovered.

P/2015 D6 (Lemmon-PANSTARRS) is a short-period comet with an orbital period of 19.6 years and perihelion distance of 4.55 AU. The comet was detected by the 1.8-m Pan-STARRS1 telescope on March 16 at 21st magnitude. Single night observations by Richard Kowalski with the 1.5-m Mount Lemmon telescope were found from February 27. Perihelion occurs on July 7 of this year. The comet will not get much brighter.

P/2015 F1 (PANSTARRS) is another short-period Pan-STARRS1 discovery having been first detected on March 21 at 19th magnitude. The comet’s current orbit is more asteroidal than cometary and suggests that C/2015 F1 is another example of a Main Belt Comet or Activated Asteroid. With a perihelion of 2.54 AU and aphelion of 4.46 AU, the comet does not leave the Main Belt. It reaches perihelion on March 20 and should not get much brighter than its current 18th magnitude.

P/2015 F2 (Polonia) was discovered by Rafal Reszelewski (Swidwin, Poland), Michal Kusiak (Zywiec, Poland), Marcin Gedek (Oborniki, Poland) and Michal Zolnowski (Krakow, Poland) on Mar. 23 UT with a remote-controlled 0.1-m f/5 astrograph of the Polonia Observatory at San Pedro de Atacama, Chile as part of a dedicated comet-search program. At discovery, Comet Polonia (the first of that name) was 16th magnitude. With an orbital period of 49 years, it is a member of the Halley family of comets. Perihelion occurs on April 29 at 1.20 AU from the Sun. The comet is intrinsically faint and may not get much brighter with the caveat that dynamically old comets like Polonia have a tendency to brighten rapidly. It is definitely one to keep an eye on.

C/2015 F3 (SWAN) was discussed above.

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

- Carl Hergenrother (ALPO Comet Section Coordinator)

 
 

ALPO COMET SECTION NEWS FOR MARCH 2015

2015-March-10

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)

 
 

ALPO COMET SECTION NEWS FOR FEBRUARY 2015

2015-February-6

Now that the Moon is out of the evening sky, it is once again a great time to observe Comet Lovejoy. Though it has faded it is still a borderline naked eye object for dark sky observers.

Evening Comets

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

Lovejoy has been quite the comet. Ever since discovery, the comet has been brightening at a rate much faster than typical. Rather than slow down, its intrinsic brightening has only accelerated throughout January. But all good things must come to an end and with the comet now receding from the Sun (1.29 to 1.37 AU this month) and Earth (0.77 to 1.31 AU) the comet has begun to fade in apparent magnitude. As of February 6th, the comet is a naked eye object at magnitude ~5.0 down from its peak at magnitude ~3.8 in mid-January. It will be interesting to see if the comet fades as rapidly as it brightened. By the end of the month, Lovejoy should still be as bright as magnitude 6.0-7.0. The comet’s motion takes it through Andromeda (Feb 1-13), Perseus (13-14), Andromeda again (14-19) and Perseus again (19-28) this month.

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]

Outbursting comet 15P/Finlay has done it again. Following its December outburst, the comet experienced another outburst in mid-January when it reached a peak brightness of ~7.5 to 8.0. The comet has rapidly faded since then and is now between magnitude 10 and 11. This is definitely one to watch for further outbursts. Finlay is an evening object moving though Pisces (Feb 1-26) and Aries (26-28).

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.

New Discoveries

Four comets were discovered since the last Section update. Each was found by the Pan-STARRS project and were fainter than 19th magnitude. Unfortunately none of them is expected to get brighter than 18th magnitude. Three [C/2015 A1 (PANSTARRS), C/2015 A2 (PANSTARRS), C/2015 B1 (PANSTARRS)] are long-period comets with the fourth [P/2015 A3 (PANSTARRS)] being a short period comet with a period of 22 years.

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

- Carl Hergenrother (ALPO Comet Section Coordinator)

 
 

COMET FINLAY IN OUTBURST AGAIN!

2015-Jan-17

Comet 15P/Finlay has undergone a second outburst. In late December the comet brightened from 10th magnitude to 8th. Reports from the past day or two show the comet brightening from 10th to 7th magnitude. All types of observations are welcome.

Finlay is an evening object in Aquarius. A PDF finder chart can be found at https://alpo-astronomy.org/cometblog/?page_id=807.

As for Comet Lovejoy, recent reports show it to be holding steady between magnitude 3.8 and 4.2.

- Carl Hergenrother (ALPO Comet Section Coordinator)

 
 

ALPO COMET SECTION NEWS FOR JANUARY 2015

2015-January-4

Latest News

Happy New Year!

2014 was a banner year for the ALPO Comet Section. The Section’s online image gallery increased from 268 images of 56 different comets to 883 images of 133 comets. An important fraction of this increase consisted of older archival images and drawings being placed online for the first time. Observers contributed 306 visual and CCD magnitude measurements for 17 comets. The best observed comets of 2014 were C/2014 E2 (Jacques) with 61 images and C/2012 K1 (PANSTARRS) with 76 magnitude measurements.

I have started producing finder charts for some of the brighter comets with the Sky Tools 3 software. The charts can be found at ‘Comet Finder Charts‘ under the list of ‘Pages’ on the Comet Section homepage.

Evening Comets

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

The brightest comet of 2014 may very well be the brightest comet of 2015 as well. As the year begins, Comet Lovejoy is around magnitude 4.5 and a nicely placed evening object for most observers. Many observers have reported seeing the comet as a faint naked eye object with a coma diameter of 20′. Telescopically, a faint, long northward pointing ion tail may be visible. Though the tail has not been very prominent visually, it has been imaged at many degrees long. Lovejoy starts January at 1.36 AU from the Sun and ends the month at perihelion (1.29 AU). Its distance from Earth starts at 0.50 AU, decreases to a close approach minimum of 0.47 AU on the 7/8th, and increases to 0.77 AU by the end of the month. Peak brightness should occur this month around magnitude 4.2 or so. Though it will fade after close approach to Earth it should still be around 5th magnitude on Jan 31. The comet rockets to the northwest through the following constellations this month: Lepus (Jan 1-2), Eridanus (2-9), Taurus (9-16), Aries (16-24), Triangulum (24-30) and Andromeda (30-31).

The plot below shows a lightcurve of C/2014 Q2 produced from visual and CCD magnitude measurements submitted to the Section. The image sequence by Gianluca Masi of Italy highlights changes in the tail of the comet during the last weeks of 2014.

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]

William Henry Finlay discovered this short-period comet with a 18-cm refractor from the Royal Observatory in South Africa in 1886. Completing an orbit roughly every 6.5 to 7 years, this marks its 15th observed apparition having been missed at 5 since discovery. Comet Finlay was expected to reach magnitude 10-11 this December/January. Surprisingly, it has undergone an outburst and was observed at 9th magnitude in late December. The comet is now back below 10th magnitude but should be watched for additional outbursts. Its distance increases from 0.98 to 1.11 AU from the Sun and reaches a minimum from the Earth of 1.39 AU mid-month. Finlay is also an evening object moving though Capricornus (Jan 1-4), Aquarius (4-20) and Pisces (20-31).

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.

New Discoveries

Three new comets were discovered since the last monthly Section News. Russian astronomer Leonid Elenin discovered his third comet, P/2014 X1 (Elenin), with a telescope in New Mexico. New Comet Elenin is on a 15-year orbit with a perihelion of 1.8 AU. It will get no brighter than 16th magnitude. C/2014 XB8 (PANSTARRS) [perihelion on 2015-Apr-05 at 3.0 AU) will remain fainter than 20th magnitude. C/2014 Y1 (PANSTARRS) may get as bright as 13th magnitude around its January 2016 perihelion at 2.2 AU. It is currently 18th magnitude.

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

- Carl Hergenrother (ALPO Comet Section Coordinator)

 
 

15P/FINLAY IN OUTBURST AND C/2014 Q2 (LOVEJOY) CONTINUES TO BRIGHTEN

2014-December-18

Short-period comet 15P/Finlay is in outburst. Predicted to be around magnitude ~10-11 as it approaches its December 27 perihelion at 0.95 AU from the Sun, observers posting on the comets-ml mailing list (https://groups.yahoo.com/neo/groups/comets-ml/info) estimate the comet is much brighter at magnitude ~8-9. Finlay is currently an evening object located about 2 degrees to the southwest of Mars.

Comet 15P/Finlay in outburst as imaged by the FRAM 0.3-m telescope in Argentina. Image posted by Jakub Cerny on comets-ml (https://groups.yahoo.com/neo/groups/comets-ml/conversations/messages/24204). Credit: FRAM team.

Long-period comet C/2014 Q2 (Lovejoy) may still be too far south for many northern observers but it is steadily heading north. Its rapid brightening trend continues with comet-ml posters reporting naked eye sightings. ALPO Comet Section contributors Willian Souza and Salvador Aguirre have watched the comet brighten from magnitude 7.6 at the start of December to 5.5 last night. It looks likely that Lovejoy will peak at around magnitude 4 to 5 in early January. Charts for both comets can be found on the German Comet Group’s comet chart site.

If the sky is clear for you this Holiday Season, try to give these two ’snowballs’ a peak. The ALPO Comet Section is happy to receive observations of these or any other comets.

- Carl Hergenrother (ALPO Comet Section)

Lightcurve of C/2014 Q2 (Lovejoy) from magnitude estimates submitted to the ALPO Comet Section by Salvador Aguirre, Willian Souza and Carl Hergenrother.

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