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

Thursday, October 6, 2016

Comets & Asteroids - Summary for August & September 2016

During the months of August & September 2016, 10 new comets were discovered, cometary activity was detected for 4 previously discovered object (earlier designated as an asteroid) and there were 3 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). 

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

- Comet Discoveries

Aug 14  Discovery of P/2016 P1 (PANSTARRS)
Aug 14  Discovery of P/2016 P2 (PANSTARRS)
Aug 29  Discovery of P/2016 N6 (PANSTARRS)
Aug 31  Discovery of C/2016 Q2 (PANSTARRS)
Sep 02   Discovery of C/2016 Q4 (KOWALSKI)
Sep 09   Discovery of C/2016 P4 (PANSTARRS)
Sep 09   Discovery of C/2016 R2 (PANSTARRS)
Sep 16   Discovery of C/2016 R3 (BORISOV)
Sep 29   Discovery of C/2016 S1 (PANSTARRS)
Sep 29   Discovery of P/2016 R4 (GIBBS)

- Cometary activity detected

Aug 10  Cometary activity detected in 2014 HU_195 = C/2014 HU_195
Aug 15  Cometary activity detected in 2015 TP_200  = P/2015 TP_200 (LINEAR)
Aug 31  Cometary activity detected in 2008 SH164   = P/2016 Q3 (LINEAR)
Sep 27   Cometary activity detected in P/2009 Q9       = P/2016 SV (PANSTARRS)

- Comet Recoveries

Aug 15  Recovery of P/2003 SQ_215 (NEAT-LONEOS) as P/2016 P3
Aug 31  Recovery of P/2005 S3 (READ) as P/2016 Q1
Sep 03   Recovery of P/2007 T6 (CATALINA) as P/2016 R1

- Other news

Aug 02 July Gamma Draconid meteor shower showed a little outburst between July 27d 23h56m and July 28d 00h23m UT as showed by IMO and CAMS meteor video camera networks and by Canadian Meteor Orbit Radar data. The observed rate translates to a peak zenith hourly rate for a visual observer (assuming a differential mass distribution index of 1.9) of about 50 meteors per hour for the period 0h-1h UT on July 28.

Credit: IMO

Aug 04 A bright sungrazer heading towards the Sun imaged by the ESA/NASA Solar & Heliospheric Observatory SOHO 03 & 04 August 2016.

Credit: SOHO

Sep 01 Comet 174P/ECHECLUS = (60558) ECHECLUS was found in outburst by P. Camilleri, brightening from magnitude r' = 17.8 to 15.2 between Aug 27.745 and 28.686 UT in a photometric aperture of radius 5".2. 

Sep 05 The search for @Philae2014 is OVER! Less than a month before the end of the mission, Rosetta’s high-resolution camera has revealed the Philae lander wedged into a dark crack on Comet 67P/Churyumov–Gerasimenko. The images were taken on 2 September by the OSIRIS narrow-angle camera as the orbiter came within 2.7 km of the surface and clearly show the main body of the lander, along with two of its three legs.

Credit: ESA/Rosetta

Sep 07 Close approach of asteroid 2016 RB1. Asteroid 2016 RB1 (estimated size of 7.3 m - 16 m) had a close approach with Earth at about 0.1 LD (Lunar Distances = ~384,000 kilometers) on 2016, September 7 at 17:20UT reaching a peak magnitude of about +12.3.

Sep 24 Time-resolved observations of the split comet 332P/Ikeya-Murakami were taken using the Hubble Space Telescope.

Credit: D. Jewitt et al.

Sep 30 ESA’s historic Rosetta mission has concluded as planned, with the controlled impact onto the comet it had been investigating for more than two years. Confirmation of the end of the mission arrived at ESA’s control centre in Darmstadt, Germany at 11:19 GMT (13:19 CEST) with the loss of Rosetta’s signal upon impact.

During the the spacecraft’s controlled descent, OSIRIS narrow-angle camera aboard Rosetta imaged comet 67P/Churyumov-Gerasimenko from an altitude of about 16 kilometers above the surface. Credit: ESA/Rosetta

A last image of comet 67P taken by Rosetta shortly before impact at an altitude of 20m above surface. The scale is 2 mm/pixel and the image measures about 96 cm across. Credit: ESA/Rosetta

by Ernesto Guido

Tuesday, September 27, 2016

BRIGHT NOVA IN LUPUS - (PNV J15290182-4449409)

Following the posting on ATel #9538 & #9539 and on the Central Bureau's Transient  Object Confirmation Page about a possible bright Nova in Lupus (TOCP Designation:  PNV J15290182-4449409)  discovered in the course of the V-band All-Sky Automated Survey for Supernova (ASAS-SN) on images obtained on Sept. 24.010 UT using the robotic 14-cm telescopes, I performed some follow-up of this object remotely through a 0.32-m f/9 reflector + CCD + f7 focal reducer of iTelescope network (MPC Code  Q62 - Siding spring, Australia).

On my images taken on September 27.4, 2016 I can confirm the presence of an optical counterpart with unfiltered magnitude about 6.5 - 7.0 (rough estimate) at coordinates:

R.A. = 15 29 01.76, Decl.= -44 49 39.7 (equinox 2000.0; UCAC-4 catalogue reference stars).

Below my image of Nova Lupus. Details on the caption. Click on the image for a bigger version.

An animation showing a comparison between my confirmation image and the archive POSS2/UKSTU Red plate (1992-07-30). Click here or on the thumbnail below for a bigger version:

NOVA IN LUPUS = PNV J15290182-4449409 photo animation1_zps24psrpgb.gif

According to the Cbet 4322 issued on September 27, 2016: "T. Bohlsen (Armidale, NSW, Australia) obtained a noisy spectrogram on Sept. 24 (time unknown) that shows H_alpha emission and also an image that yielded magnitude V = 6.8; he surmised from this that the variable does appear to be a galactic nova."

by Ernesto Guido

Wednesday, September 7, 2016

Close Approach of Asteroid 2016 RB1

The asteroid 2016 RB1 was discovered  (at ~ magnitude +19) on 2016, September 05 by Mt. Lemmon Survey (MPC code G96) with a 1.5-m reflector + 10K CCD. 

Asteroid 2016 RB1 has an estimated size of 7.3 m - 16 m (based on the object's absolute magnitude H=27.8) and it will have a close approach with Earth at about 0.1 LD (Lunar Distances = ~384,000 kilometers) or 0.0003 AU (1 AU = ~150 million  kilometers) on 2016, September 7 at 17:20UT and it will reach a peak magnitude of about +12.3. Radio astronomers will try to  observe it as 2016 RB1 could be a really strong radar target during its close approach.

I performed some follow-up measurements of this object on 2016, September 07.6, remotely from the Q62 iTelescope network (Siding Spring, Australia) through a 0.4-m f/3.5 reflector + CCD. Below you can see our image taken with the asteroid at about magnitude +13 and moving at ~ 503 "/min. At the moment of its close approach on Sep 07, around 17UT, 2016 RB1 will move at ~ 2716 "/min (or about  45.2 deg/hour). The asteroid is trailed in the image due to its fast speed. Click on the image below to see a bigger version. (North is up, East is to the left). 

by Ernesto Guido