Saturday, November 30, 2019

Comets & Asteroids - Summary for Sept & Oct 2019

During the 2-month period September through October 2019, 9 new comets were discovered, cometary activity was detected for 1 previously discovered object (earlier designated as asteroids) and there were 6 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

Sep 10 Discovery of C/2019 Q3 (PANSTARRS)            (CBET 4665)
Sep 12 Discovery of C/2019 Q4 (BORISOV)                 (CBET 4666)
Oct 05 Discovery of P/2019 S2 (PANSTARRS)             (CBET 4673)
Oct 05 Discovery of P/2019 S3 (PANSTARRS)             (CBET 4674)
Oct 16 Discovery of C/2019 T3 (ATLAS)                       (CBET 4678)
Oct 23 Discovery of C/2019 T4 (ATLAS)                       (CBET 4681)
Oct 23 Discovery of C/2019 T5 (ATLAS)                       (CBET 4682)
Oct 24 Discovery of P/2019 T6 (PANSTARRS)             (CBET 4684)
Oct 28 Discovery of P/2019 U4 (PANSTARRS)             (CBET 4688)

- Cometary activity detected

Oct 06 Cometary activity detected in 2018 DO4 =  C/2018 DO_4 (LEMMON)  (CBET 4675)

- Comet Recoveries

Sep 08 Recovery of P/2007 T4 (GIBBS) as P/2019 R2                   (CBET 4662)
Sep 09 Recovery of P/2008 Y1 (BOATTINI) as P/2019 R1            (CBET 4663)
Sep 27 Recovery of P/2006 R1 (SIDING SPRING) as P/2019 S1  (CBET 4671)
Oct 25 Recovery of P/2006 W1 (GIBBS) as P/2019 U1                 (CBET 4685)
Oct 28 Recovery of P/2006 F1 (KOWALSKI) as P/2019 U2          (CBET 4686)
Oct 28 Recovery of P/2004 WR_9 (LINEAR) as P/2019 U3          (CBET 4687)

- Other news

Sep 04 New paper on Arxiv by D. Jewitt & J. Luu: "Disintegrating In-Bound Long-Period Comet C/2019 J2".

Credit: Jewitt & Luu

Sep 16 Analysis of a bright flash in Jupiter’s atmosphere observed by an amateur astronomer in August 2019 has revealed that the likely cause was a small asteroid with a density typical of stony-iron meteors. The impact is estimated to have released energy equivalent to an explosion of 240 kilotons of TNT – around half the energy released in the 2013 Chelyabinsk event at Earth.

Credit: E. Chappel/R. Hueso

Oct 07 Saturn Surpasses Jupiter After The Discovery Of 20 New Moons. A team led by Carnegie's Scott S. Sheppard has found 20 new moons orbiting Saturn.  This brings the ringed planet’s total number of moons to 82, surpassing Jupiter, which has 79. 

Credit: NASA/JPL-Caltech/Space Science Institute/Sartorio/Shutterstock

Oct 08 The 2019 #NobelPrize in Physics has been awarded with one half to James Peebles “for theoretical discoveries in physical cosmology” and the other half jointly to Michel Mayor and Didier Queloz “for the discovery of an exoplanet orbiting a solar-type star”.

Credit: Mayor & Queloz

Oct 28 Beautiful images from VLT/SPHERE of the fourth biggest asteroid, Hygiea, found a big surprise: an almost spherical shape. It was hit in the past by a big impact which shattered and reassembled it while still fluid.

Credit: Vernazza et al.

by Ernesto Guido