Monday, February 29, 2016

Comets & Asteroids - Summary for February 2016

During the month of February 2016,  3 new comets were discovered, there were 2 recoveries and cometary activity was detected for 2 previously discovered objects (earlier designated as asteroids). New fragments of comet  P/2015 Y2 = P/2010 V1 (IKEYA-MURAKAMI) (see previous post) reported. According to a paper available on Arxiv, at least 17 fragments have been identified. Moreover the binary nature of asteroid (2535) Hämeenlinna and a previously unknown shower of naked-eye meteors, now known as the Volantids, have been reported (see below for more about these news). "Current comet magnitudes" & "Daily updated asteroid flybys" pages are available at the top of this blog (or just click on the underline text here).

The dates below refer to the date of issuance of CBET (Central Bureau Electronic Telegram)  which reported the official news & designations.

- Comet Discoveries

Feb 14  Discovery of C/2016 C1 (PANSTARRS)
Feb 15  Discovery of P/2016 BA14 (PANSTARRS)*
Feb 19  Discovery of C/2016 C2 (NEOWISE)

Comet P/2016 BA14 - M.Kelley/S.Protopapa/UMD

*The comet 252P/LINEAR will pass perihelion on 2016 Mar. 15 and make an historic close approach to the Earth on 2016 March 21 at 0.036 AU (or 13.9 LD), which is one of the closest cometary approaches to the Earth on record. In the meantime, on 2016 Jan 22, asteroid 2016 BA14 was discovered by the Pan-STARRS survey and it will have a close approach with Earth on 2016 March 22 at 0.0237 (or 9.2 LD). This asteroid and comet 252P have very similar orbital elements (a fact first noted by D. Denisenko on Comets Mailing List). This similarity prompted observers to image asteroid 2016 BA14 with the 4.3-m Lowell Observatory's Discovery Channel Telescope that led to the discovery of its cometary activity (new designation P/2016 BA14).  Close approach by P/2016 BA14 will be the third closest on record and the closest flyby of a comet in 246 years (since the 1770 passage by Comet D/1770 L1 -Lexell- at 5.9 LD). These objects are very probably related to one another, fragments from a past larger comet; observations in program (by the way also with the HST space telescope) will provide further confirmation.


- Comet Recoveries

Feb 06  Recovery of P/2008 Y2 (GIBBS) as P/2016 A9
Feb 15  Recovery of P/2006 G1 (McNAUGHT) as P/2016 B2

- Cometary activity detected

Feb 01  Cometary activity detected in 2015 ER61 = C/2015 ER61 (PANSTARRS)
Feb 02  Cometary activity detected in 2015 PD229 = P/2015 PD229 (ISON-Cameron) 

Comet P/2015 PD229 (ISON-Cameron) - NOAO DECam DECAL

- Asteroid & Meteor news

Feb 20  CBET 4261 reports that CAMS video camera surveillance of meteor showers in the Southern Hemisphere (CAMS New Zealand) detected a previously unknown shower of naked-eye meteors that peaked at the time of the local new year's eve celebrations. One out of three meteors that night came from this shower. The new shower is now known as the Volantids, named after the constellation Volans, the flying fish, from where the meteoroids appear to approach us. The parent body has not yet been identified. The source is a Jupiter-family comet that must now be in a relatively highly inclined orbit. A copy of the paper submitted to for publication in WGN, the Journal of the International Meteor Organization (JIMO) is available here.

Direction from which meteors approached us on December 31 (and next night). Credit: CAMS

Feb 25  CBET 4262 reports that minor planet (2535) Hämeenlinna is a binary system with an orbital period of 21.23 +/- 0.01 hr.  The primary shows a period of 3.23106 +/- 0.00006 hr and has a lightcurve amplitude of 0.10 mag at solar phases 2-8 degrees, suggesting a nearly spheroidal shape.

by Ernesto Guido

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