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

Monday, March 13, 2017

New Comet: C/2017 E4 (LOVEJOY)

CBET nr. 4373, issued on 2017, March 13, announces the discovery of a comet (magnitude ~15) by Terry James Lovejoy on three CCD 8-s exposures taken five minutes apart starting on Mar. 9.684 UT with a Celestron C14 reflector operating at f/1.9 (+ QHY9 camera). The new comet has been designated C/2017 E4 (LOVEJOY)

I performed follow-up measurements of this object, while it was still on the neocp. Stacking of 10 unfiltered exposures, 30 seconds each, obtained remotely on 2017, March 10.7 from Q62 (iTelescope network) through a 0.50-m f/6.8 astrograph + CCD + focal reducer, shows that this object is a comet with a diffuse coma nearly 15 arcsec in diameter.

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



M.P.E.C. 2017-E86 assigns the following preliminary parabolic orbital elements to comet C/2017 E4: T 2017 Apr. 23.3; e= 1.0; Peri. =  87.21; q = 0.49;  Incl.= 88.23

 Discovery image set from March 9.68, 2017. Credit. T. Lovejoy


by Ernesto Guido

Sunday, March 5, 2017

New Comet: C/2017 E1 (Borisov)

CBET nr. 4369, issued on 2017, March 04, announces the discovery of a comet (magnitude ~17) by Gennadii Vladimirovich Borisov on three unfiltered 120-s exposures obtained on Mar. 1.10 UT with a 0.4-m f/2.3 astrograph at the "Mobil Astronomical Robotics Genon" Observatory (MARGO) near Nauchnij. The new comet has been designated C/2017 E1 (Borisov)

I performed follow-up measurements of this object, while it was still on the neocp. Stacking of 20 unfiltered exposures, 30 seconds each, obtained remotely on 2017, March 1.5 from H06 (iTelescope network) through a 0.43-m f/6.8 reflector + CCD + f/4.5 focal reducer, shows that this object is a comet with a diffuse coma nearly 30 arcsec in diameter.

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



M.P.E.C. 2017-E42 assigns the following preliminary parabolic orbital elements to comet C/2017 E1: T 2017 Apr. 9.8; e= 1.0; Peri. =  151.90; q = 0.90;  Incl.= 14.54


by Ernesto Guido

Thursday, February 2, 2017

Comets & Asteroids - Summary for December 2016

During the month of December 2016, 1 new comet has been 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).  

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

- Comet Discoveries

Dec 21  Discovery of C/2016 X1 (LEMMON)

- Other news

Dec 13 Image of the Kuiper belt object Orcus and its moon Vanth posted on twitter by M. Brown: "The ALMA radio telescope/interferometer detects the heat coming from Orcus ~4 billion miles away and separately from its moon Vanth."

Credit: ALMA - M. Brown


Dec 20 Man-To Hui & David Jewitt published on Arxiv the follwing paper "Non-Gravitational Acceleration of the Active Asteroids" where they present an astrometric investigation of 18 active asteroids in search of non-gravitational acceleration. "Comets can exhibit non-gravitational accelerations caused by recoil forces due to anisotropic mass loss. So might active asteroids."


Dec 23 CBET 4339 reports that a group of observers obtained lightcurves of the minor planet (12008) KANDRUP  during July 2007, which were typical of binary synchronous asteroids. "The period is around 1.371 day.  "The monitoring until January 2008 showed a regular evolution of the signature of mutual phenomenona.  Other observations were obtained between August and October 2010, showing lightcurves with similar properties.  In December 2013, the amplitude of variation was similar to those of the other oppositions, but some events were possibly missed.  As observed on 2016 Dec. 2 and 7, the mutual phenomenona are 0.5-magnitude deep and their duration is around 4 hours; an observed brightness minimum occurred on Dec. 6.930 UT.  These are indications that the mutual orbit of the system components is close to the ecliptic plane, like that of minor planet (4492) Debussy". 

Dec 26 Vera Rubin, American astronomer, passed away (July 23, 1928 – December 26, 2016). Her work on galaxy rotation rates led to theory of dark matter.

Rubin looking through a telescope. Credit: Vassar College, courtesy AIP Emilio Segrè Visual Archives

by Ernesto Guido

Wednesday, January 11, 2017

New Comet: C/2017 A3 (Elenin)

CBET nr. 4344, issued on 2017, January 11, announces the discovery of a comet (magnitude ~18.2) by L. Elenin on three CCD images obtained with 0.4-m f/2.4 reflector + CCD at the ISON-SSO Observatory at Siding Spring on Jan. 5.4 UT. The new comet has been designated C/2017 A3 (Elenin)

I performed follow-up measurements of this object, while it was still on the neocp. Stacking of 20 unfiltered exposures, 120 seconds each, obtained remotely on 2017, Jan 06.5 from Q62 (iTelescope network) through a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer, shows that this object is a comet with a compact coma nearly 10 arcsec in diameter elongated toward PA 40.

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




M.P.E.C. 2017-A75 assigns the following preliminary parabolic orbital elements to comet C/2017 A3: T 2017 Jan. 20.6; e= 1.0; Peri. =  301.87; q = 3.91;  Incl.= 99.12


by Ernesto Guido