Tuesday, July 25, 2017

New Comet: C/2017 O1

CBET nr. 4414, issued on 2017, July 24, announces the discovery of a comet (magnitude ~15.3) in the course of the "All-Sky Automated Survey for Supernovae" (ASASSN) program, from images taken with the 14-cm "Cassius" survey telescope at Cerro Tololo on July 19.32 UT. The new comet has been designated C/2017 O1. 

I performed follow-up measurements of this object, while it was still on the neocp. Stacking of 10 unfiltered exposures, 60 seconds each, obtained remotely on 2017, July 23.7 from Q62 (iTelescope network) through 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer, shows that this object is a comet with a sharp central condensation surrounded by diffuse coma about 3 arcmins in diameter

My confirmation image (click on it for a bigger version)



Below you can see the discovery image by ASASSN survey

Credit: ASASSN


M.P.E.C. 2017-O45 assigns the following preliminary parabolic orbital elements to comet C/2017 O1: T 2017 Oct. 14.3; e= 1.0; Peri. =  20.29; q = 1.51;  Incl.= 39.75

Below you can see a graph generated using the software Orbitas and showing the predicted magnitude for this comet (click on the image for a bigger version). Visual estimates have the comet at mag. ~10 on July 24, 2017. Syuichi Nakano, Sumoto, Japan, notes on CBET 4414 that this comet could reach total visual magnitude 7 during September-November. A word of caution: as always with comets, the future magnitudes reported here are only indicative.



by Ernesto Guido 

Wednesday, June 28, 2017

Comets & Asteroids - Summary for April 2017

During the month of April 2017, 7 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

Apr 02 Discovery of C/2017 D5 (PANSTARRS)
Apr 02 Discovery of C/2017 E5 (LEMMON)
Apr 02 Discovery of C/2017 F1 (LEMMON)
Apr 06 Discovery of C/2017 F2 (PANSTARRS)
Apr 06 Discovery of P/2017 G1 (PANSTARRS)
Apr 21 Discovery of P/2017 G2 (PANSTARRS)
Apr 21 Discovery of C/2017 G3 (PANSTARRS)

- Other news 

Apr 04 More #Rosetta #OpenAccess papers in special issue of Monthly Notices of the Royal Astronomical Society.

Apr 06 New extreme TNO, 2013 SY99, from @OSSOSurvey: a=730±40 au, q=50.0 au, i=4.2°, e=0.93, H=6.8. 

Credit: Michele Bannister


Apr 14 Closest images ever taken of Saturn's moon, Atlas, imaged on April 12, 2017, by @CassiniSaturn

Credit: NASA/JPL-Caltech/Space Science Institute

Apr 18 New paper on Arxiv by Julio A. Fernández et al.: "Physical and dynamical properties of the anomalous comet 249P/LINEAR"

Apr 20 Radar images of 2014 JO25 from @NAICobservatory reveal shadows, possible boulders, and more on this 650+ m (twice as big as previously estimated) asteroid rotating in ~4.5 hours: "Arecibo radar observations revealed the asteroid to have a lumpy, two-lobed shape very reminiscent of Comet 67P/Churyumov–Gerasimenko recently visited by the European Space Agency's Rosetta mission."

Credit: Arecibo Obs./NASA/NSF


Apr 29 CBET 4387 reports that minor planet (2881) is a binary system with an orbital period of 20.42 +/- 0.01 hr.  Mutual eclipse/occultation events that are 0.09- to 0.15-magnitude deep indicate a secondary-to-primary mean-diameter ratio of 0.29 +/- 0.02. 


by Ernesto Guido

Sunday, June 4, 2017

New Comet: C/2017 K4 (ATLAS)

CBET nr. 4397, issued on 2017, June 01, announces the discovery of a comet (magnitude ~17) by the "Asteroid Terrestrial-impact Last Alert System" (ATLAS) Team on CCD exposures taken on May 26.5 with the ATLAS 0.5-m f/2.0 Schmidt telescope at Haleakala. The new comet has been designated C/2017 K4 (ATLAS)

I performed follow-up measurements of this object, while it was still on the neocp. Stacking of 10 unfiltered exposures, 120 seconds each, obtained remotely on 2017, May 29.4 from Q62 (iTelescope network) through 0.43-m f/6.8 reflector + CCD, shows that this object is a comet with a diffuse coma nearly 10 arcsec in diameter

My confirmation image (click on it for a bigger version)



Discovery animation by ATLAS Survey

Credit: The ATLAS Project

M.P.E.C. 2017-L04 assigns the following preliminary parabolic orbital elements to comet C/2017 K4 (ATLAS): T 2018 Jan. 13.3; e= 1.0; Peri. =  20.42; q = 2.54;  Incl.= 17.19

by Ernesto Guido

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: ESA/NASA/SOHO/LASCO C3

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

Wednesday, April 19, 2017

Comets & Asteroids - Summary for February 2017

During the month of February 2017, 4 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

Feb 04 Discovery of C/2017 B3 (LINEAR)
Feb 04 Discovery of P/2017 B4 (PANSTARRS)
Feb 12 Discovery of C/2017 C1 (NEOWISE)
Feb 20 Discovery of C/2017 C2 (PANSTARRS)


- Other news 

Feb 02 At this link, animation by L. Elenin showing the egress of near-earth asteroid 2017 BS32 from Earth's shadow. 

Feb 3 CBET 4353, CBET 4356 (Feb 09), CBET 4361 (Feb 14) report that the following minor planets are binaries systems: (226514) 2003 UX_34, (2486) METSAHOVI, (27675) 1981 CH.

Feb 09 & Feb 13 Two new papers on arXiv about active asteroid P/2016 J1 (PANSTARRS): "Split Active Asteroid P/2016 J1 (PANSTARRS)" & "The splitting of double-component active asteroid P/2016 J1 (PANSTARRS)". Click on the image below for a bigger version.

Credits: Man-To Hui, David Jewitt, Xinnan Du

Feb 09 New impact crater spotted on Mars: "This new crater, which formed explosively at the point of impact, has a diameter of roughly 8 meters (about 25 feet), but its surrounding blast zone and ejecta extend over a kilometer (about one mile) beyond the crater itself. This new impact was discovered using the lower-resolution Context Camera (CTX), also on board Mars Reconnaissance Orbiter. An older CTX image of this region from May 2012 shows a uniformly dust-covered surface, while a newer CTX image from September 2016 reveals the crater’s dark blast zone.". Click on the image below for a bigger version.

Credits: NASA/JPL/University of Arizona 

Feb 11 Unknown fragment from Comet 73P discovered in outburst by T. Noel. Click on the image below for a bigger version.



Feb 13 Radar images of asteroid 2017 BQ6 were obtained on Feb. 6 and 7 with NASA’s 70-meter antenna at GSSR. "They reveal an irregular, angular-appearing asteroid about 660 feet (200 meters) in size that rotates about once every three hours. The images have resolutions as fine as 12 feet (3.75 meters) per pixel.Asteroid 2017 BQ6 safely passed Earth on Feb. 6 at 10:36 p.m. PST (1:36 a.m. EST, Feb. 7) at about 6.6 times the distance between Earth and the moon (about 1.6 million miles, or 2.5 million kilometers). It was discovered on Jan. 26 by the NASA-funded Lincoln Near Earth Asteroid Research (LINEAR) Project, operated by MIT Lincoln Laboratory on the Air Force Space Command’s Space Surveillance Telescope at White Sands Missile Range, New Mexico." Click on the image below for a bigger version.

Credits: Credits: NASA/JPL-Caltech/GSSR

Feb 15 Arecibo Radar Observatory captures revealing images of Comet 45P/Honda-Mrkos-Pajdusakova :  "The comet’s shape is probably two lobes and is seen here to be about 1.3 km in size. Gif below composed of thirteen delay-Doppler images of Comet 45P/HMP after 2 hours of observation. The new radar observations have revealed Comet 45P/HMP to be somewhat larger than previously estimated. The radar images suggest a size of about 1.3 km (0.8 mi) and that it rotates about once every 7.6 hours."

Credits: Arecibo Observatory/NASA/NSF

Feb 15 On this day, 4 years ago  the Chelyabinsk meteor (15 FEBRUARY 2013). Click on the image below for a bigger version.

Credits: Alex Alishevskikh - CC BY-SA 2.0


by Ernesto Guido

Saturday, March 18, 2017

Comets & Asteroids - Summary for January 2017

During the month of January 2017, 4 new comets were discovered, cometary activity was detected for 1 previously discovered object (earlier designated as an asteroid) and there was 1 comet recovery. "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

Jan 6  Discovery of C/2017 A1 (PANSTARRS)
Jan 07 Discovery of P/2017 A2 = P/2011 A5 (PANSTARRS)
Jan 11 Discovery of C/2017 A3 (ELENIN)
Jan 28 Discovery of P/2017 B1 = 2010 EY_90 (LEMMON)



- Cometary activity detected

Jan 29 Cometary activity detected in 2016 VZ_18 = C/2016 VZ_18 (PANSTARRS)

- Comet Recoveries

Jan 30  Recovery of P/2010 J5 (McNAUGHT) as P/2017 B2

- Other news

Jan 8 CBET 4342, CBET 4345 (Jan. 12), CBET 4346 (Jan. 14) & CBET 4347 (Jan. 28) report that the following minor planets are binaries systems: (4296) VAN WOERKOM, (12326) SHIRASAKI, (6186) ZENON, (163693) ATIRA

Credit: Arecibo Observatory

by Ernesto Guido