During the 5-month period Aug through Dec 2017, 22 new comets were discovered, cometary activity was detected for 5 previously discovered object (earlier designated as an asteroid) and there were 5 comet recoveries. "Current comet magnitudes" & "Daily updated asteroid flybys" pages are available at the top of this blog (or just click on the underline text here). See below for the "Other news" section.
The dates below refer to the date of issuance of CBET (Central Bureau Electronic Telegram) which reported the official news & designations.
- Comet Discoveries
Aug 17 Discovery of P/2017 P1 (PANSTARRS)
Aug 23 Discovery of C/2017 P2 (PANSTARRS)
Sep 22 Discovery of P/2017 R1 (PANSTARRS)
Sep 22 Discovery of C/2017 S2 (PANSTARRS)
Sep 27 Discovery of C/2017 S3 (PANSTARRS)
Sep 29 Discovery of P/2017 S5 (ATLAS)
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| Comet P/2017 S5 - Credit: ATLAS survey |
Oct 08 Discovery of C/2017 S6 (CATALINA)
Oct 08 Discovery of C/2017 S7 (LEMMON)
Oct 16 Discovery of C/2017 T1 (HEINZE)
Oct 25 Discovery of C/2017 T2 (PANSTARRS)
Oct 28 Discovery of P/2017 S8 (PANSTARRS)
Oct 28 Discovery of P/2017 S9 (PANSTARRS)
Oct 28 Discovery of C/2017 T3 (ATLAS)
Oct 29 Discovery of C/2017 U2 (FULS)
Nov 13 Discovery of P/2017 U3 (PANSTARRS)
Nov 20 Discovery of C/2017 U4 (PANSTARRS)
Dec 03 Discovery of C/2017 U5 (PANSTARRS)
Dec 19 Discovery of C/2017 W2 (LEONARD)
Dec 19 Discovery of P/2017 W3 (GIBBS)
Dec 19 Discovery of C/2017 X1 (PANSTARRS)
Dec 31 Discovery of C/2017 Y1 (PANSTARRS)
Dec 31 Discovery of C/2017 Y2 (PANSTARRS)
- Cometary activity detected
Aug 03 Following the announcement on CBET 4415 of the possible connection of 2017 MB_1 and the alpha Cap meteor shower, P. Birtwhistle, Great Shefford, Berkshire, England, re-examined his CCD images of 2017 MB_1 taken using a 0.40-m Schmidt-Cassegrain reflector on several dates. There are no traces of cometary activity on co-added exposures taken on July 4.04 (10 min exposure time) and 5.04 UT (30 min total exposure), but on July 25.11, stacked exposures totalling 7.2 min show a possible very faint, thin, straight tail in p.a. 260 deg, appearing detached from the main object, starting at a distance of 35" and extending to 90" from 2017 MB_1. The images from July 25 were taken in brightening nautical twilight (solar altitude -12.8 to -12.0 degrees), but he is reasonably confident that the possible tail is real and not an artifact.
Aug 11 Cometary activity detected in the NEOWISE images containing minor planet 2014 XK_6
Aug 25 Cometary activity detected in 2007 RS_41 = P/2017 Q2 (LONEOS)
Sep 28 Cometary activity detected in 2006 UR_111 (SPACEWATCH) = P/2017 S4
Dec 13 Cometary activity detected in 2000 XO_8
- Comet Recoveries
Aug 03 Recovery of P/2010 D1 (WISE) as P/2017 O2
Aug 22 Recovery of P/2008 T4 (HILL) as P/2017 Q1
Aug 26 Recovery of P/2012 T1 (PANSTARRS) as P/2017 O3
Sep 20 Recovery of P/2010 P4 (WISE) as P/2017 S1
Nov 20 Recovery of P/2011 VJ_5 (LEMMON) as P/2017 W1
Oct 09 CBET 4442 reports that the following name has been voted upon by the IAU Working Group on Small Body Nomenclature for a recently discovered comet:
Designation (Name) Discovery Reference
351P/Wiegert-PANSTARRS CBET 4439*
C/2017 O1 (ASASSN) CBET 4414
351P/Wiegert-PANSTARRS CBET 4439*
C/2017 O1 (ASASSN) CBET 4414
* Further to CBET 4298, G. V. Williams (Minor Planet Center) has linked a reported comet from 2007 to comet P/2016 P2. The comet has been given the permanent number 351P and year designations P/2016 P2 = P/1998 U8 = P/2007 R11.
Further to CBETs 4376 and 4439, the following permanent numbers have been assigned to short-period comets based upon their being securely observed at multiple returns to perihelion.
Designation/Name Provisional Designations Reference
352P/Skiff P/2000 S1 = P/2017 L1 CBET 4402
353P/McNaught P/2009 S2 = P/2017 M1 CBET 4404
354P/LINEAR P/2010 A2 = P/2017 B5 CBET 4405
355P/LINEAR-NEAT P/2004 T1 = P/2017 M2 CBET 4406
356P/WISE P/2010 D1 = P/2017 O2 CBET 4441
357P/Hill P/2008 T4 = P/2017 Q1 CBET 4422
358P/PANSTARRS P/2012 T1 = P/2017 O3 CBET 4425
359P/LONEOS P/2007 RS_41 = P/2017 Q2 CBET 4424
360P/WISE P/2010 P4 = P/2017 S1 CBET 4429
361P/Spacewatch P/2006 UR_111 = P/2017 S4 CBET 4433
362P/(457175) P/2008 GO_98 CBET 4411
- Other news
Aug 06 Asteroid 2012 TC4 has been recovered. Close approach on Oct. 12 at ~50200 km. Images from 2012 available here while images & animation of Oct. 2017 close approach are available here.
Aug 17 New paper on Arxiv by Jian-Yang Li et al. : "The Unusual Apparition of Comet 252P/2000 G1 (LINEAR) and Comparison with Comet P/2016 BA14 (PanSTARRS)"
Sep 01 Goldstone Radar Images of asteroid (3122) Florence. Florence will approach within 0.047 AU on 2017 September 1 (FOTO). Radar Reveals Two Moons Orbiting Asteroid Florence.
Sep 16 New paper on Arxiv by Snodgrass et al. : "The Main Belt Comets and Ice in the Solar System"
Sep 20 NASA’s Hubble Space Telescope helped an international team of astronomers find that an unusual object in the asteroid belt is, in fact, two asteroids orbiting each other that have comet-like features. These include a bright halo of material, called a coma, and a long tail of dust. The time-lapse video below, assembled from a set of Hubble Space Telescope photos, reveals two asteroids orbiting each other that have comet-like features. The asteroid pair, called 2006 VW139/288P, was observed in September 2016, just before the asteroid made its closest approach to the Sun.
Sep 29 NASA's Hubble Observes the Farthest Active Inbound Comet Yet Seen - Paper by Jewitt et al. available here.
Oct 04 CBET 4435, CBET 4436, CBET 4440 (Oct.09) & CBET 4459 (Dec. 08) report that the following minor planets are binaries systems: 2017 RV1; (23621) 1996 PA; (10132) LUMMELUNDA; (3378) SUSANVICTORIA
Oct 11 New paper on Arxiv by Meech et al: "CO-Driven Activity in Comet C/2017 K2 (PANSTARRS)"
Oct 25 The first clear case of an interstellar object A/2017 U1. According to CBET 4450 "inadvertently designated as comet C/2017 U1 on MPEC 2017-U181 (and changed to A/2017 U1) with no claimed cometary appearance by any observers appears to have hyperbolic orbital elements". A/2017 U1 was discovered Oct. 19 by the University of Hawaii's Pan-STARRS 1 telescope on Haleakala during the course of its nightly search for Near-Earth Objects for NASA. appears to have originated from outside the solar system, coming from somewhere else in our galaxy. If so, it would be the first "interstellar object" to be observed and confirmed by astronomers. According to MPEC 2017-V17: "the object A/2017 U1 receives the permanent designation 1I and the name ʻOumuamua. The name, which was chosen by the Pan-STARRS team, is of Hawaiian origin and reflects the way this object is like a scout or messenger sent from the distant past to reach out to us (ʻou means reach out for, and mua, with the second mua placing emphasis, means first, in advance of). Correct forms for referring to this object are therefore: 1I; 1I/2017 U1; 1I/ʻOumuamua; and 1I/2017 U1 (ʻOumuamua).
Oct 27 Comet 96P/Machholz in the LASCO C3 camera on ESA/NASA SOHO.
Dec 08 New Outburst of 174P/Echeclus
Dec 22 Radar images of asteroid (3200) Phaethon via Arecibo Radar
Aug 06 Asteroid 2012 TC4 has been recovered. Close approach on Oct. 12 at ~50200 km. Images from 2012 available here while images & animation of Oct. 2017 close approach are available here.
Aug 17 New paper on Arxiv by Jian-Yang Li et al. : "The Unusual Apparition of Comet 252P/2000 G1 (LINEAR) and Comparison with Comet P/2016 BA14 (PanSTARRS)"
Sep 01 Goldstone Radar Images of asteroid (3122) Florence. Florence will approach within 0.047 AU on 2017 September 1 (FOTO). Radar Reveals Two Moons Orbiting Asteroid Florence.
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| Credit: Goldstone |
Sep 16 New paper on Arxiv by Snodgrass et al. : "The Main Belt Comets and Ice in the Solar System"
Sep 20 NASA’s Hubble Space Telescope helped an international team of astronomers find that an unusual object in the asteroid belt is, in fact, two asteroids orbiting each other that have comet-like features. These include a bright halo of material, called a coma, and a long tail of dust. The time-lapse video below, assembled from a set of Hubble Space Telescope photos, reveals two asteroids orbiting each other that have comet-like features. The asteroid pair, called 2006 VW139/288P, was observed in September 2016, just before the asteroid made its closest approach to the Sun.
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| Credits: NASA, ESA, and J. DePasquale and Z. Levay (STScI) |
Sep 29 NASA's Hubble Observes the Farthest Active Inbound Comet Yet Seen - Paper by Jewitt et al. available here.
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| Credits: NASA, ESA, and D. Jewitt (UCLA) |
Oct 04 CBET 4435, CBET 4436, CBET 4440 (Oct.09) & CBET 4459 (Dec. 08) report that the following minor planets are binaries systems: 2017 RV1; (23621) 1996 PA; (10132) LUMMELUNDA; (3378) SUSANVICTORIA
Oct 11 New paper on Arxiv by Meech et al: "CO-Driven Activity in Comet C/2017 K2 (PANSTARRS)"
Oct 25 The first clear case of an interstellar object A/2017 U1. According to CBET 4450 "inadvertently designated as comet C/2017 U1 on MPEC 2017-U181 (and changed to A/2017 U1) with no claimed cometary appearance by any observers appears to have hyperbolic orbital elements". A/2017 U1 was discovered Oct. 19 by the University of Hawaii's Pan-STARRS 1 telescope on Haleakala during the course of its nightly search for Near-Earth Objects for NASA. appears to have originated from outside the solar system, coming from somewhere else in our galaxy. If so, it would be the first "interstellar object" to be observed and confirmed by astronomers. According to MPEC 2017-V17: "the object A/2017 U1 receives the permanent designation 1I and the name ʻOumuamua. The name, which was chosen by the Pan-STARRS team, is of Hawaiian origin and reflects the way this object is like a scout or messenger sent from the distant past to reach out to us (ʻou means reach out for, and mua, with the second mua placing emphasis, means first, in advance of). Correct forms for referring to this object are therefore: 1I; 1I/2017 U1; 1I/ʻOumuamua; and 1I/2017 U1 (ʻOumuamua).
Oct 27 Comet 96P/Machholz in the LASCO C3 camera on ESA/NASA SOHO.
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| Credit: SOHO |
Dec 08 New Outburst of 174P/Echeclus
Dec 22 Radar images of asteroid (3200) Phaethon via Arecibo Radar
by Ernesto Guido
Thanks for the updates.
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