Wednesday, May 31, 2017

New Impact Flash on Jupiter

On May 26, 2017 (between 19:24.6 and 19:26.2 Universal Time) a new possible impact flash on Jupiter was imaged by Sauveur Pedranghelu, a French amateur astronomer from Corsica. According to a preliminar analysis by Marc Delcroix (who runs a Jovian impact flashes detection project) this flash, detected in the North polar area of Jupiter, seems shorter than the others (~0.7s vs 1-2s) and displayed two brightness peaks. (click on the images below for a bigger version).

The image by Pedranghelu was then posted online as a call for observations of Jupiter obtained in the same time interval to exclude the possibility that the flare might have been caused by an artefact or flashing satellite. Few hours after the posting, two other observers from Germany (Andre Fleckstein & Thomas Riessler) confirmed independently from one another the finding with their own images. 

Below you can see an animation made by Thomas Riessler using his Jupiter observations showing the impact flash on Jupiter. (click on it for a bigger version). The impact area imaged in the hours after the reported flash showed NO remnants of the impact.

Credit: T. Riessler 

This is not the first time that we have seen something slam into Jupiter, beginning with a fireball recorded by Voyager 1 as it flew past in 1979 (see image below) and the famous impact of Comet Shoemaker-Levy 9 in 1994. 

March 5, 1979 - Fireball in Jupiter's Atmosphere by Voyager 1
Credit: Cook & Duxbury

In this blog we reported about all the recent cases starting from the event of July 19, 2009 (a scar left on Jupiter by an unseen impact observed by Anthony Wesley), of June 03, 2010 (impact flash observed by Anthony Wesley and Christopher Go), of August 20, 2010 (impact flash observed by Masayuki Tachikawa & Aoki Kazuo), of September 10, 2012 (impact flash observed  by Dan Petersen and George Hall), of March 17, 2016 (impact flash observed by Gerrit Kernbauer and John McKeon).

The role of planet Jupiter as a shield protecting Earth from getting hit by such objects is still controversial and it has been discussed in depth in a series of articles by Jonathan Horner and Barrie Jones (Jupiter - friend or foe?).

by Ernesto Guido

Tuesday, May 23, 2017

Comets & Asteroids - Summary for March 2017

During the month of March 2017, 8 new comets were discovered. "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

Mar 01 Discovery of P/2017 D1 (FULS)
Mar 01 Discovery of C/2017 D2 (BARROS)
Mar 01 Discovery of C/2017 D3 (ATLAS)
Mar 01 Discovery of P/2017 D4 (PANSTARRS)
Mar 04 Discovery of C/2017 E1 (BORISOV)
Mar 07 Discovery of C/2017 E2 (XUYI)
Mar 13 Discovery of C/2017 E3 (PANSTARRS)
Mar 13 Discovery of C/2017 E4 (LOVEJOY)

 Click on the images below for a bigger version

C/2017 E1 (BORISOV) - E. Guido
C/2017 E4 (LOVEJOY) - E. Guido

Discovery images of C/2017 D3 (ATLAS) - Credits: The ATLAS Project

- Other news 

Credits: Z. Sekanina & R. Kracht

Mar 03 A new, bright Sungrazing comet racing towards the Sun via @SungrazerComets


Credits: Kiss et al.

Mar 09 CBET 4371 & CBET 4374 (Mar 19) report that the following minor planets are binaries systems: (2825) CROSBY & (1798) WATTS

Mar 09 PAN, the second-innermost moon of Saturn, imaged by @CassiniSaturn on March 07, 2017

Credits: NASA/JPL-Caltech/Space Science Institute

Mar 28 New paper on arXiv by Jewitt & al.: "Anatomy of an Asteroid Break-Up: The Case of P/2013 R3"

Credits: Jewitt & al.

Mar 29 CBET 4376 reports that the following names have been voted upon by the IAU Working Group on Small Body Nomenclature for recently discovered comets:

Designation (Name)                          Discovery Reference
P/2015 PD229 (Cameron-ISON)             CBET 4251
C/2014 HU195 (Valdes-TOTAS)             CBET 4294

Further to CBET 4343, 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              Discovery/Recovery Reference       
348P/PANSTARRS      P/2017 A2 = P/2011 A5                        CBET 4341
349P/Lemmon              P/2010 EY90 = P/2017 B1                    CBET 4349
350P/McNaught           P/2010 J5 = P/2017 B2                         CBET 4352

Mar 30 New paper on NATURE by Wiegert et al. about the first retrograde co-orbital asteroid: 2015 BZ509: "A retrograde co-orbital asteroid of Jupiter" (see animation below)

by Ernesto Guido