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

Wednesday, December 28, 2016

Comets & Asteroids - Summary for November 2016

During the month of November 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

Nov 03  Discovery of C/2016 U1 (NEOWISE)


- Other news

Nov 02 Newly discovered asteroid 2016 VA came to about 90.000 km from the Earth’s surface on the second day of November, reaching magnitude  12. It crossed the Earth shadow for a few minutes (between 23:24-23:35 UT on Nov 01, just 0.3 LD from Earth), challenging  astronomers to observe a peculiar “asteroidal eclipse”. Below you can see an animation showing this spectacular event as observed by G. Masi (Virtual Telescope Project). According to Masi: "Each frame comes from a 5-seconds integration. At the eclipse time, the asteroid was moving with an apparent motion of 1500"/minutes"



Nov 07 Roy Panther (1926 - 2016), British visual comet discoverer passed away. Obituary by N. James: "Roy was the discoverer of comet C/1980 Y2 (1980u). The discovery was made visually using a 0.20m, f/4 Newtonian at 1850 UT on Christmas day 1980 when the comet was a 9th magnitude object near M56. The discovery was confirmed that evening by Mike Hendrie and George Alcock and it was Roy's first success after 601 hours of searching.  Martin Mobberley has an interesting Sky at Night on his Youtube channel which includes an interview with Roy."

Roy Panther with his 8-inch 'old discoverer'

Nov 07 K. Battams & M. Knight published on Arxiv a summary paper of the more than 3,000 sungrazing and near-Sun comets discovered in coronagraph images returned by the Solar and Heliospheric Observatory (SOHO), since its launch in December 1995.

Credit: K. Battams & M. Knight


Nov 10 CBET 4336 reports that minor planet (5112) KUSAJI  is a binary system with an orbital period of 20.74 +/- 0.01 hr.  The primary shows a period of 2.7995 +/- 0.0001 hr and has a lightcurve amplitude of 0.12 mag at solar phases 4-8 degrees, suggesting a nearly spheroidal shape.


by Ernesto Guido

Friday, November 11, 2016

Comets & Asteroids - Summary for October 2016

During the months of October 2016, 3 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).  

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

- Comet Discoveries

Oct 11  Discovery of C/2016 T1 (MATHENY)
Oct 13  Discovery of C/2016 T2 (MATHENY)
Oct 18  Discovery of C/2016 T3 (PANSTARRS)


- Other news

Oct 14 Klim Ivanovich Churyumov (1937 - 2016), astronomer and co-discoverer (with Svetlana Gerasimenko) of comet #67P passed away on October 14, 2016 

Oct 17 The third-largest object known beyond Neptune, 2007 OR10, has a moon. The discovery was reported in a poster by Gábor Marton, Csaba Kiss, and Thomas Mueller presented at the joint meeting of the European Planetary Science Congress and the Division for Planetary Sciences of the American Astronomical Society (DPS/EPSC) in Pasadena, California. The Hubble Space Telescope took the photo below of 2007 OR10 on September 18, 2010. Later analysis of the images revealed the presence of a moon (red circle).

Credit: NASA / STScI / Wesley Fraser / Gábor Marton et al.


Oct 26 Lutz D. Schmadel (1942 - 2016), author of the Dictionary of Minor Planet Names, died on Friday October 21, 2016



Oct 27 Catalog of Known Near-Earth Asteroids Tops 15,000, with an average of 30 new discoveries added each week. This milestone marks a 50 percent increase in the number of known NEAs since 2013, when discoveries reached 10,000 in August of that year. The 15,000th near-Earth asteroid is designated 2016 TB57. It was discovered on Oct. 13 by observers at the Mount Lemmon Survey.



Oct 29 #TeamRadar at Arecibo imaged binary asteroid 2003 YT1 on the morning of Oct 29, 2016. Asteroid 2003 YT1 was discovered by the Catalina Sky Survey in December 2003. This asteroid approached within 0.035 au (13.5 lunar distances) on October 31. Radar observations at Arecibo in May 2004 revealed that this is a binary system with a rapidly-rotating primary and a secondary whose orbital and rotation periods appear to be asynchronous.  The primary has a rotation period of 2.34 h and the upper bound on the rotation period of the  secondary is about 6 h. In the new obtained image below, the faint smudge at the top is the satellite moving in its orbit over 2 hours. 

Credit: @AreciboRadar


by Ernesto Guido