Wednesday, January 16, 2019

ACTIVE ASTEROID (6478) GAULT

CBET 4594 (issued on 2019, January 08) announces the serendipitous discovery by the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) team of unusual activity associated with the inner main-belt minor planet (6478) which appears to have developed a lengthening tail or trail. 

"A median combination of seven 30-s exposures on 2019 Jan. 5 shows a tail or trail 135" long in p.a. 290 degrees. The tail/trail first appears in individual ATLAS exposures on 2018 Dec. 8, as identified by Denneau, with a median combined 120-s exposure showing a tail 30" long in p.a. 290 degrees.  There is no evidence of a tail in previous ATLAS imaging in January 2018."

Credit: ATLAS - discovery image

On January 08.7, I performed follow-up measurements of this object. Stacking of 10 unfiltered exposures, 120 seconds each, obtained remotely from Q62 (iTelescope network) through a 0.43-m f/6.8 astrograph + CCD, shows a tail about 2' and 30" long in PA 292.

My follow-up image (click on it for a bigger version)



Asteroid (6478) GAULT was discovered on 1988, May 12 by astronomers Carolyn & Eugene Shoemaker at the Palomar Observatory in California. It was named for American planetary geologist Donald Gault:

   Credit: Dictionary of Minor Planet Names - Schmadel

The active asteroids represent a newly recognized class of small body in the solar system: their peculiarity lies in having both the orbital characteristics of asteroids, residing in orbits interior to Jupiter’s and having the Tisserand parameter substantially larger than 3, and the physical properties of comets, in the form of comae or tails. 

Credit: D. Jewitt

The active asteroids have been referred to as ‘main-belt comets’ and ‘disrupted asteroids’ previously: the new designation is preferred both because some of the known cases are not located in the main belt and because the nature of the activity. Actually the causes of the activity are thought to be many and varied. As regards (6478) GAULT at this stage we can't rule out sublimation (or any other of the suggested mechanisms) in favor of an impact or viceversa. Hopefully more data will help sort out the cause of its activity. See the excellent David Jewitt's Active Asteroids webpage for more info about these fascinating objects and his paper "The Active asteroids" (The Astronomical Journal, 2012 March). 

Below you can see active asteroid (6478) GAULT imaged on 2019, January 11 at @INGLaPalma.


Credit: INGLaPalma



by Ernesto Guido

Thursday, December 20, 2018

New Comet C/2018 Y1 (Iwamoto)

CBET 4588 & MPEC 2018-Y52, issued on 2018, Dec. 20,  announce the discovery of a comet (magnitude ~12) by M. Iwamoto (MPC code 872) in images taken on 2018 Dec 18.8. The new comet has been designated C/2018 Y1 (Iwamoto).

I performed follow-up measurements of this object, while it was still on the PCCP webpage. Stacking of 5 unfiltered exposures, 20 seconds each, obtained remotely on 2018, December 20.5 from H06 (T20 - iTelescope network) through a 0.1-m f/5.0 astrograph + CCD, shows that this object is a comet with a diffuse coma about 1.5 arcmin in diameter and sharp central condensation.

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



MPEC 2018-Y52 assigns the following preliminary parabolic orbital elements to comet C/2018 Y1: T 2019 Jan. 27.16; e= 1.0; Peri. =  354.05; q = 1.14;  Incl.= 160.69

Below you can see a graph generated using the software Orbitas and showing the predicted magnitude (in red) versus the maximum height (for Northern Hemisphere). (click on the image for a bigger version). Preliminar orbit has the comet 0.2 AU from Earth with a peak magnitude of about 6 at the beginning of February 2019! (as always with comets, the future magnitudes reported here are only indicative).  Elongation at the beginning of February 2019 will be 160 degrees (maximum height will be very good for Northern Hemisphere at peak that is around 80 degrees, good for Southern until few days before peak then decreasing fast).




Congrats to Masayuki Iwamoto for his third comet discovery (the last one was just one month ago)! (see here for more info about his previous discoveries C/2018 V1 & C/2013 E2)

Below you can see the discovery image taken by M. Iwamoto at 05:11am of December 19, 2018 (Japanese Time) and the discoverer itself with his equipment.

Credit: M. Iwamoto


Masayuki Iwamoto - Credit: Hoshinavi


by Ernesto Guido

Sunday, November 11, 2018

New Comet C/2018 V1 (Machholz-Fujikawa-Iwamoto)

CBET 4569 (issued on 2018, November 08) and  MPEC 2018-V151 (2018, November 11),  announce the discovery of a 10th-magnitude comet by  Donald E. Machholz (Colfax, CA, U.S.A) and independently by Shigehisa Fujikawa (Kan'onji, Kagawa, Japan) and Masayuki Iwamoto (Awa, Tokushima, Japan).

The new comet has been designated C/2018 V1 (Machholz-Fujikawa-Iwamoto).

- D. Machholz reported his VISUAL DISCOVERY on Nov. 7.531 UT with a 0.47-m reflector (113x). He also observed the comet with similar appearance on Nov. 8.533

- Shigehisa Fujikawa  found the object (with no description provided) on Nov. 7.82 UT on a CCD image obtained with a 120-mm-f.l. f/3.5 lens. His discovery was reported to the Central Bureau's TOCP webpage, which produced the provisional designation TCP J12192806-0211143

- Masayuki Iwamoto discovered the new object on images obtained on Nov. 7.841 with a 10-cm f/4.0 Pentax SDUF II telephoto lens and a Canon EOS 6D camera; Iwamoto called it a possible comet of mag 10 with approximate position R.A. = 12h19m30s, Decl. = -2d11' (equinox 2000.0) and his observations was reported on TCP J12192806-0211143 TOCP webpage. He added that he also observed it one minute later and detected no movement.

Prompted by the Iwamoto's remark in the TOCP webpage about the possible cometary nature of this transient I decided to perform  follow-up measurements of this object. The telescope I chose was T14 astrograph in New Mexico due to its wide field FOV (155.8 x 233.7 arc-mins). In fact as only 1 astrometric position was available at that time and my observation was scheduled 16 hours after it was taken, in case of a comet it was important to have as much field as possible around that only reported astrometry point.

As it happens, it was a comet and I found it about 51 arcmin from the reported astrometry available (60 arcmin is 1 degree). Single unfiltered 60 second exposure, obtained remotely on 2018, November 08.5 from H06 (iTelescope network) through a 0.10-m f/5 reflector + CCD, shows that this object is a comet with a diffuse coma about 2 arcmin in diameter.

My astrometry of this new comet was reported to MPC in order to allow it to be put on "The Possible Comet Confirmation Page" (TPCCP) for fellow observers around the world to observe it.


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



Below the list of observations in the order they came (following the posting on the TOCP and after that on the Minor Planet Center's NEOCP webpages) as reported on CBET 4569 (click on it for a bigger version):



Below you can see a short animation spanning about 35 minutes (70 x 30sec exposures) obtained on Nov. 9.16 by fellow Italian amateur astronomer Alfonso Noschese from his "Osservatorio Elianto" (MPC code K68 - 0.3-m f/4.0 Newtonian reflector + CCD; AstroCampania association). (click on it for a bigger version):



On November 11.16, A. Noschese imaged again comet C/2018 V1 that in the meantime developed a nice ion tail clearly visible in his images below:




M.P.E.C. 2018-V151 assigns the following preliminary parabolic orbital elements to comet C/2018 V1: T 2018 Dec. 3.51; e= 1.0; Peri. =  88.83; q = 0.38;  Incl.= 143.96

Below you can see a graph generated using the software Orbitas and showing the predicted magnitude (in red) versus the maximum height (for Northern Hemisphere). (click on the image for a bigger version). Visual estimates have the comet at mag. ~8.0 on November 12, 2018 (as always with comets, the future magnitudes reported here are only indicative).




Congrats to Don Machholz, Shigehisa Fujikawa and Masayuki Iwamoto!

This is 12th comet discovery for Machholz, coming 746 search hours after his discovery of C/2010 F4 (cf. IAUC 9132); the 2nd comet discovery for Iwamoto (see here for more info about his previous discovery C/2013 E2) ; the 7th comet discovery for Fujikawa



UPDATE - November 13, 2018

We imaged again comet C/2018 V1 on November 12.16 from "Osservatorio Elianto" (MPC code K68 - 0.3-m f/4.0 Newtonian reflector + CCD). The ion tail is  increasingly evident as you can see in the image & animation below. (click on the images for a bigger version)




by Ernesto Guido

Wednesday, October 31, 2018

Comets & Asteroids - Summary for Sept & Oct 2018

During the 2-month period September through October 2018, 3 new comets were discovered and there  were 5 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). 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

Sep 16 Discovery of C/2018 R3 (LEMMON)     (CBET 4556)
Sep 16 Discovery of C/2018 R4 (FULS)            (CBET 4557)
Sep 18 Discovery of C/2018 R5 (LEMMON)     (CBET 4559)


- Comet Recoveries

Sep 08  Recovery of P/2001 R6 (LINEAR-SKIFF) as P/2018 R1 (CBET 4552)
Sep 16  Recovery of P/2008 O2 (McNAUGHT) as P/2018 P6      (CBET 4554)
Sep 16  Recovery of P/2011 W2 (RINNER) as P/2018 R2           (CBET 4555)
Sep 18  Recovery of P/2007 V1 (LARSON) as P/2018 S1           (CBET 4558)
Oct 06  Recovery of P/2006 D1 (HILL) as P/2018 T1                   (CBET 4560)


- Other news

Sep 14 CBET 4553, CBET 4561 (Oct 07), CBET 4562 (Oct 14), CBET 4563 (Oct 18), CBET 4565 (Oct 23), CBET 4566 (Oct 23) & CBET 4567 (Oct 26) report that the following minor planets are binaries systems: (25015) 1998 QN2 & (5402) KEJOSMITH & (18527) 1996 VJ30 & (2178) KAZAKHSTANIA & (100015) 1989 SR7 & (6100) KUNITOMOIKKANSAI & 2018 TF3.

Sep 25 Third most energetic meteor of the year (1.9 kT) was observed, filmed and recorded South of Reunion & Mauritius islands, on September 25, 14h10m UT.

Image of the September 25, 2018, 14h 10m UT fireball extracted from a Youtube video of the event.

Oct 02 New Extremely Distant Solar System Object Found During Hunt for PLANET X. The newly found object, called 2015 TG387, was discovered about 80 astronomical units (AU) from the Sun. 

2015 TG387 as it moves across the sky, as seen through the Subaru telescope - Credit: S. Sheppard



Oct 23 An outburst of October Draconids was widely observed between Oct. 8d17h55m and 9d06h05m UTC (solar longitude 195.146-195.647 degrees, equinox J2000). Visual observations gathered by the International Meteor Organization suggest a peak Zenith Hourly Rate (ZHR) of 122 +/- 5 meteors/hr at 23.6 +/- 0.1 hr UTC on Oct. 8, and a full-width-at-half-maximum (FWHM) duration of 4.0 +/- 0.4 hr.  (CBET 4564)

Composite picture of 2018 Draconid outburst - Credit: Juraj Toth

by Ernesto Guido

Wednesday, September 26, 2018

Comets & Asteroids - Summary for August 2018

During the month of August 2018, 4 new comets were discovered, cometary activity was detected for 1 previously discovered object (earlier designated as asteroids) and there  were 2 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). 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

Aug 17 Discovery of C/2018 O1 (ATLAS)     (CBET 4543)
Aug 19 Discovery of P/2018 P3 (PANSTARRS) (CBET 4548)
Aug 19 Discovery of P/2018 P4 (PANSTARRS) (CBET 4549)
Aug 19 Discovery of C/2018 P5 (PANSTARRS) (CBET 4550)

- Cometary activity detected

Aug 14 Cometary activity detected in 2018 KJ3 = C/2018 KJ3 (LEMMON)

- Comet Recoveries

Aug 13  Recovery of P/2010 A1 (HILL) as P/2018 P1 (CBET 4538)
Aug 13  Recovery of P/2001 T3 (NEAT) as P/2018 P2 (CBET 4539)

- Other news

Aug 07  Asteroid (162173) Ryugu imaged on August 07, 2018 from a distance of about 1 km by @haya2e_jaxa - For more info see http://bit.ly/2M3KKCr  #astronomy #asteroids


Credit: JAXA

Aug 10 S. S. Sheppard, Carnegie Institution for Science, reports the discovery of a satellite to the trans-Neptunian object 2013 FY27.  The satellite was detected about 0".17 at a position angle of 135 degrees from the primary in four 545-s images taken with the WFPC3/UVIS instrument with the Hubble Space Telescope during 2018 Jan. 15.058-15.104 UT.  The satellite is about 3 magnitudes fainter than the primary in the F350LP filter.  The projected separation of the satellite is about 9800 km from the primary (CBET 4537)

Aug 17 M. S. P. Kelley and D. Bodewits, University of Maryland; and Q.-Z. Ye, Infrared Processing and Analysis Center, California Institute of Technology, on behalf of the Zwicky Transient Facility (ZTF) Solar System Working Group, report an outburst of comet 64P/Swift-Gehrels in ZTF images taken with the Oschin 1.2-m Schmidt telescope at Palomar. The post-outburst brightness (7"-radius aperture) is r' = 13.88 +/- 0.02, indicating an outburst strength of at least 2.7 mag (CBET 4544)

Aug 20 A Better Look At Asteroid 216 Kleopatra (based on the findings described in the article entitled A revised shape model of asteroid (216) Kleopatra, recently published in the journal Icarus).

Credit: Shepard et al.

Aug 22 Has Anyone Found a Lost Comet?! (based on the papaer "Finding Long Lost Lexell's Comet: The Fate of the First Discovered Near-Earth Object")

Aug 28 NASA's New Horizons spacecraft has made its first detection of its next flyby target, the Kuiper Belt object 2014 MU69 nicknamed Ultima Thule, more than four months ahead of its New Year's 2019 close encounter.  

Credits: NASA/JHUAPL/SwRI

by Ernesto Guido

Thursday, August 30, 2018

Comets & Asteroids - Summary for June & July 2018

During the 2-month period June through July 2018, 7 new comets were discovered, cometary activity was detected for 1 previously discovered object (earlier designated as asteroids) 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). 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

Jun 09 Discovery of P/2018 L1 (PANSTARRS) (CBET 4521)
Jun 09 Discovery of C/2018 L2 (ATLAS)          (CBET 4522)
Jun 22 Discovery of P/2018 L4 (PANSTARRS) (CBET 4527)
Jul 02 Discovery of P/2018 L5 (LEONARD)     (CBET 4528)
Jul 02 Discovery of C/2018 M1 (CATALINA)   (CBET 4529)
Jul 07 Discovery of C/2018 N1 (NEOWISE)     (CBET 4532)
Jul 16 Discovery of C/2018 N2 (ASASSN)        (CBET 4534)




- Cometary activity detected

Jun 11 Cometary activity detected in 2018 EN4 = C/2018 EN4 (NEOWISE)

- Comet Recoveries

Jun 14  Recovery of P/2005 R1 (NEAT) as P/2018 L3 (CBET 4526)

- Other news

Jun 01 A New Impact Crater – Mars Reconnaissance Orbiter (MRO) keeps finding new impact sites on Mars. This one occurred within the dense secondary crater field of Corinto Crater.

Credit: NASA/JPL/University of Arizona



Jun 02 Small Asteroid 2018 LA (aka ZLAF9B2) IMPACTED Earth on 02 June 2018 

Credit: (CREDIT: Mt. Lemmon Survey - CSS).



Credit: Kokotanekova et al



Jun 09 CBET 4523 & CBET 4536 (Jul 20) report that the following minor planets are binaries systems: (15745) YULIYA & (4666) DIETZ

Jun 12 New paper on Arxiv by Masiero et al.: "Small and Nearby NEOs Observed by NEOWISE During the First Three Years of Survey: Physical Properties".

Jun 14 JAXA Hayabusa2 spacecraft starts sending images of asteroid (162173) Ryugu. Below you can see some images taken from a distance of 700km on June 14, 2018 and from a distance of about 6km on July 20, 2018.

Credit: JAXA



Credit: Jaxa

Jun 26 An asteroid impact triggered an avalanche on Mars as imaged by HiRISE camera on the Mars Reconnaissance Orbiter.

Credit: NASA/JPL/University of Arizona


Jun 27 New results indicate interstellar nomad `Oumuamua is a comet. The first interstellar object discovered in the Solar System, is moving away from the Sun faster than expected.

Credit: Micheli et al.


Jul 13 Radar images of the binary asteroid 2017 YE5 via @AreciboRadar & Green Bank Observatory on June 25 show it consists of two separate objects in orbit around each other that are roughly the same size.


Credit: Arecibo/GBO/NSF/NASA/JPL-Caltech

Jul 17 Jupiter has 10 more moons we didn't know about — and they're weird. The planet now has 79 known moons, including a tiny oddball on a collision course with its neighbours.

Jul 20 Comet C/2017 S3 (PANSTARRS) imaged by Michael Jaeger on July 20, 2018 @ Jauerling, Austria.

Credit: M. Jaeger



by Ernesto Guido

Monday, July 16, 2018

New Comet: C/2018 N2 (ASASSN)

MPEC 2018-O01, issued on 2018, July 16,  announces the discovery of a comet (magnitude ~16.1) in the course of the "All-Sky Automated Survey for Supernovae" (ASASSN) program, in images taken 2018 July 7-11 with the 14-cm "Cassius" survey telescope at Cerro Tololo. The new comet has been designated C/2018 N2 (ASASSN)

I performed follow-up measurements of this object, while it was still on the PCCP webpage. Stacking of 10 unfiltered exposures, 60 seconds each, obtained remotely on 2018, July 15.7 from Q62 (iTelescope network) through a 0.43-m f/6.8 astrograph + CCD, shows that this object is a comet with a diffuse coma about 15 arcsec in diameter.

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



For a different elaboration of this image please click here.

M.P.E.C. 2018-O01 assigns the following preliminary parabolic orbital elements to comet C/2018 N2: T 2019 Oct. 4.09; e= 1.0; Peri. =  23.85; q = 3.00;  Incl.= 78.31

This is the second comet discovered by ASASSN Survey (more info about their first comet are here).

by Ernesto Guido