Sunday, August 7, 2016

Comets & Asteroids - Summary for July 2016

During the month of July 2016,  1 new comet has been discovered and there were 4 comet recoveries. An international team of astronomers discovered a new dwarf planet (designated 2015 RR245) orbiting  in the disk of small icy worlds beyond Neptune. The Team Radar at Arecibo observed the Near-Earth asteroid (154244) 2002 KL6. "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

July 18  Discovery of C/2016 N4 (MASTER)

 - Comet Recoveries

July 04 Recovery of P/2009 K1 (GIBBS) as P/2016 M2
July 04 Recovery of P/2008 J3 (McNAUGHT) as P/2016 N1
July 06 Recovery of P/2008 T1 (BOATTINI) as P/2016 N2
July 18 Recovery of P/2007 R3 (GIBBS) as P/2016 N3



- Other news

July 11 An international team of astronomers discovered a new dwarf planet orbiting in the disk of small icy worlds beyond Neptune. Designated 2015 RR245 by the International Astronomical Union's Minor Planet Center, it was found using the Canada-France-Hawaii Telescope on Maunakea, Hawaii,  as part of the ongoing Outer Solar System Origins Survey (OSSOS).  The Minor Planet Center describes the object as the 18th largest in the Kuiper Belt. Click on the image below to see a bigger version of the rendering of the orbit of RR245 (orange line). Objects as bright or brighter than RR245 are labeled. The blue circles show the projected orbits of the major planets.

Credit: Alex Parker - OSSOS team.

July 16 The Team Radar at Arecibo observed the Near-Earth asteroid (154244) 2002 KL6. This asteroid was discovered by Near-Earth Asteroid Tracking (NEAT) program in May 2002. It approached Earth to within 0.07 au (27 lunar distances) on July 22, 2016. Its absolute magnitude is around 17.4, which suggests a diameter within a factor of two of 1 km, assuming an optical albedo of 18%. Its rotation period is around 4.6 h based on lightcurves. 




July 27 Rosetta is set to complete its mission in a controlled descent to the surface of its comet on 30 September. The mission is coming to an end as a result of the spacecraft’s ever-increasing distance from the Sun and Earth. "It is heading out towards the orbit of Jupiter, resulting in significantly reduced solar power to operate the craft and its instruments, and a reduction in bandwidth available to downlink scientific data.  Instead of risking a longer hibernation that is unlikely to be survivable, and after consultation with Rosetta’s science team in 2014, it was decided that Rosetta would follow its lander Philae down onto the comet. The final hours of descent will enable Rosetta to make many once-in-a-lifetime measurements, including very-high-resolution imaging, boosting Rosetta’s science return with precious close-up data achievable only through such a unique conclusion." In the meantime Rosetta is still observing the comet. Below you can see comet 67P imaged by the OSIRIS instrument on 27 July 2016 from a distance of 8km. Click onthe image for a bigger version.

Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

by Ernesto Guido

Monday, July 4, 2016

Comets & Asteroids - Summary for June 2016

During the month of June 2016,  2 new comets were discovered and there was 1 comet recovery. A small asteroid, 2016 HO3, has been discovered in an orbit around the sun that keeps it as a constant companion of Earth, and it will remain so for centuries to come. On June 2nd a small asteroid (1-3 meters wide) hit Earth's atmosphere and exploded over Arizona. Amateur astronomer and comet discoverer Rolf G. Meier died on June 26th, 2016 after a short battle with cancer. "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

June 05  Discovery of C/2016 K1 (LINEAR)
June 24  Discovery of C/2016 M1 (PANSTARRS)



- Comet Recoveries

June 06 Recovery of P/2010 N1 (WISE) as P/2016 GE_216


- Other news

June 02 On June 2nd at 3:56 a.m. local (MST) time (10:56 UT), a small asteroid (estimated diameter about 1-3 meters) hit Earth's atmosphere and exploded over Arizona. The airburst shook the ground below and produced a flash of light 10x brighter than a full Moon. A week later, one of Arizona State University’s top meteorite experts was off on a team expedition in the Arizona wilderness on an Apache homeland, braving bug bites, bears and mountainous terrain. After three nights camping and 132 hours of searching, the team found 15 meteorites, ranging in size from a medium-sized strawberry to a pea. A video with more info on this expedition is available here.


Credit: Mike Lerch on June 2, 2016 @ Front yard of home in Phoenix Az USA

Credit: Charlie Leight/ASU Now

June 15 A small asteroid, 2016 HO3, has been discovered in an orbit around the sun that keeps it as a constant companion of Earth, and it will remain so for centuries to come. This asteroid, first spotted on April 27, 2016, by the Pan-STARRS 1 survey, measures between 40 and 100 meters (120 to 300 feet) in diameter and it poses no threat to Earth.  As it orbits the sun, this new asteroid, designated 2016 HO3, appears to circle around Earth as well. It is too distant to be considered a true satellite of our planet, but it is the best and most stable example to date of a near-Earth companion, or "quasi-satellite."

Credit: NASA/JPL-Caltech 

It became a quasi-satellite about a century ago, and will follow our planet around the Sun for the next three centuries, looping around us once a year. Its yearly loop will then unhook from Earth, starting to follow a horseshoe path with respect to our planet, which will last for several millennia. In this animated picture below by A. Vitagliano, the frame is rotated synchronously with the revolution of Earth, which therefore moves along the short green segment located 1 AU above the Sun, while the other inner planets are hidden. The yellow loop represents one yearly path of the asteroid, and each frame is taken at 1 year intervals for a total span of 999 years. 

Credit: Aldo Vitagliano - Solex

June 26 Amateur astronomer and comet discoverer Rolf G. Meier (1953–2016) died on June 26th after a short battle with cancer. He was the discoverer of four comets which bear his name (Meier 1978, 1979, 1980, 1984). He received the RASC’s Chant Medal in 1979 for his contributions.

Rolf Meier with the 40cm Ottawa Centre telescope


by Ernesto Guido

Monday, June 6, 2016

New Comet: C/2016 K1 (LINEAR)

CBET nr. 4282, issued on 2016, June 05, announces the discovery of an apparently asteroidal object (magnitude ~18.5) found on CCD images taken on May 31 with the 3.5-m f/1 Space Surveillance Telescope on Atom Peak in the White Sands Missile Range, NM, USA, in the course of the LINEAR survey. This object has been found to cometary appearance by CCD astrometrists elsewhere after it was posted on the Minor Planet Center's NEOCP webpage. The new comet has been designated C/2016 K1 (LINEAR).

We 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 2016, June 04.4 from H06 (iTelescope network - New Mexico) through a 0.43-m f/6.8 astrograph + CCD + f/4.5 focal reducer, shows that this object is a comet with a compact coma nearly 8 arcsec in diameter elongated toward PA 225.

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




M.P.E.C. 2016-L34 assigns the following preliminary parabolic orbital elements to comet C/2016 K1: T 2016 July 14.36; e= 1.0; Peri. = 18.66; q = 2.29;  Incl.= 90.94


by Ernesto Guido

Tuesday, May 31, 2016

Comets & Asteroids - Summary for May 2016

During the month of May 2016,  3 new comets were discovered and cometary activity was detected for 1 previously discovered object (earlier designated as an asteroid). 

NASA's Hubble Space Telescope imaged comet 252P/LINEAR just after it swept by Earth on March 21, 2016 while the Subaru Telescope serendipitously captured high-resolution images of comet 67P/Churyumov-Gerasimenko. Moreover a non-gravitational acceleration has been detected influencing the motion of minor planet (85990) (see below for more about these news). "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

May 09  Discovery of P/2016 J1 (PANSTARRS)*
May 09  Discovery of C/2016 J2 (DENNEAU)
May 31  Discovery of P/2016 J3 (STEREO)

* According to the discovery CBET,  follow-up images obtained at the 3.6-m Canada-France-Hawaii Telescope atop Mauna Kea on May 6.43 showed a second comet in the field. "The two components are moving at nearly identical rates in nearly identical directions (both about 0".6/minute in p.a. about 314 deg). The brighter component (designated component A) displays a clear and quite thin tail about 10" long in p.a. 250 deg in the May 6.43 images.  The fainter object (designated component B) also displays a clear but broader tail of similar length, oriented toward p.a. about 210 deg". The available astrometry for both components and ephemerides appear on MPEC 2016-J90

- Cometary activity detected

May 29  Cometary activity detected in 2016 KA = C/2016 KA (CATALINA)

Credit: P. Birtwhistle 

- Other news

May 12  Astronomers using NASA's Hubble Space Telescope captured images of comet 252P/LINEAR just after it swept by Earth on March 21.

Credit: NASA, ESA, and J.-Y. Li (Planetary Science Institute)

May 12 Hyper Suprime-Cam on the Subaru Telescope serendipitously captured high-resolution images of comet 67P/Churyumov-Gerasimenko during the inaugural queue-mode observations last March. The camera was scheduled to observe a distant compact galaxy when the chance came up to capture a view of the comet, and the images reveal fine details in the comet's coma and tails.

Credit: Subaru Telescope, NAOJ


May 25 Animation of the yearly discovery rate of #NEOs by size (H). Data from @MinorPlanetCtr via @JLGalache



May 27 CBET 4279 reports that a non-gravitational acceleration has been detected influencing the motion of minor planet (85990)

And finally a cartoon by the illustrator and cartoonist Tom Gauld + a Chelyabinsk event mention in "Zero K", the new novel by Don DeLillo (h/t to Paolo Simonetti

Credit: Tom Gauld


Credit: Don DeLillo
Credit: Don DeLillo






















by Ernesto Guido

Saturday, April 30, 2016

Comets & Asteroids - Summary for April 2016

During the month of April 2016,  2 new comets were discovered and cometary activity was detected for 1 previously discovered object (earlier designated as an asteroid). NASA's Hubble Space Telescope spotted a small, dark moon orbiting Makemake, the second brightest icy dwarf planet — after Pluto — in the Kuiper Belt. Pioneer comet observer Elizabeth (Pat) Roemer died on April 09. Moreover the discovery of the binary nature of asteroid (5674) Wolff and the images of a new satellite of asteroid (130) Elektra have been reported (see below for more about these news). "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

Apr 05  Discovery of P/2016 G1 (PANSTARRS)
Apr 08  Discovery of P/2015 HG_16 (PANSTARRS)*

*G. V. Williams, Minor Planet Center, noted that the 2016 April 3 observations of  this comet appeared to belong to a supposedly asteroidal object found a year ago by Pan-STARRS1 on 2015 Apr. 20, 21, and 24 (and then given the minor-planet designation 2015 HG_16 on MPS 603395 and 603396)

- Cometary activity detected

Apr 24  Cometary activity detected in 2015 WZ = C/2015 WZ (PANSTARRS)

- Other news 

Apr 09  Pioneer comet observer Elizabeth (Pat) Roemer died on April 09. Astronomer Jim Scotti wrote this memory on Facebook: "With great sadness I must report the death of my friend and mentor Elizabeth (Pat) Roemer (1929-2016) this morning. She joined the Lunar and Planetary Lab in 1966. She led the world in the observation of faint comets and recovered 79 short period comets in an age where computing ephemerides and reducing astrometric observations were all done by hand. I learned so much from her beginning in Astronomy 400b which emphasized planetary astronomy and introductory celestial mechanics and was always a great help in later years in learning how to observe comets and asteroids".

Apr 23  CBET 4272 reports that minor planet (5674) Wolff is a binary system with an orbital period of 93.7 +/- 0.2 hr. Mutual eclipse/occultation events that are up to 0.70-magnitude deep indicate a lower limit on the secondary-to-primary mean-diameter ratio of 0.80.  

Apr 25  Astronomers have discovered a new satellite orbiting the main belt asteroid (130) Elektra (first announced via CBET 4036 on December 17, 2014). The team, led by Bin Yang (ESO, Santiago, Chile), imaged it using the extreme adaptive optics instrument, SPHERE, installed on the Unit Telescope 3 of ESO’s Very Large Telescope at Cerro Paranal, Chile. This new, second moonlet of (130) Elektra is about 2 kilometres across and has been provisionally named S/2014 (130) 1, making (130) Elektra a triple system. Exploiting the unprecedented sensitivity and spatial resolution of the instrument SPHERE, the team also observed another triple asteroid system in the main belt, (93) Minerva. Full paper now available here

Credit: Yang/ESO


Apr 26  NASA's Hubble Space Telescope has spotted a small, dark moon orbiting Makemake, the second brightest icy dwarf planet — after Pluto — in the Kuiper Belt. The moon — provisionally designated S/2015 (136472) 1 and nicknamed MK 2 — is more than 1,300 times fainter than Makemake. MK 2 was seen approximately 21,000 km (13,000 miles) from the dwarf planet, and its diameter is estimated to be 161 km (100 miles) across. Makemake is 1400 km (870 miles) wide. The dwarf planet, discovered in 2005, is named for a creation deity of the Rapa Nui people of Easter Island.

Credit: NASA, ESA, Parker & Buie (SRI), Grundy (Lowell Obs), K. Noll (NASA GSFC)


by Ernesto Guido

Thursday, March 31, 2016

Comets & Asteroids - Summary for March 2016

During the month of March 2016,  3 new comets were discovered. On March 17, 2016 a new impact flash on Jupiter has been captured by amateur astronomers. Moreover, delay-doppler images of asteroid 2016 DV1 (on March 03, 2016) and of comet P/2016 BA14 (on March 22, 2016) have been obtained by Goldstone Solar System Radar.(see below for more about these news). "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

Mar 11  Discovery of C/2016 E1 (PANSTARRS)
Mar 16  P/2015 B4 (LEMMON-PANSTARRS)
Mar 16  C/2016 E2 (KOWALSKI)


Scientists using the Goldstone Solar System Radar in California's Mojave Desert observed comet P/2016 BA14 during its historic flyby. Close approach of March 22, 2016 by P/2016 BA14 has been the third closest on record and the closest flyby of a comet in 246 years (for more info about P/2016 BA14 see our previous post). Radar images from the flyby indicate that the comet is about 1 kilometer in diameter. Moreover data collected by V. Reddy using the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii indicate that the comet reflects less than 3 percent of the sunlight that falls on its surface. 

Radar images of comet P/2016 BA14 - Credit: NASA/JPL-Caltech/GSSR



Comet P/2016 BA14 - Credit: NASA/JPL-Caltech/GSSR



- Asteroid & Meteors news

On March 17, 2016 (at 00:18:35UT) a possible impact flash on Jupiter was imaged independently by 2 amateur astronomers: Gerrit Kernbauer (Mödling, Austria) & John McKeon (Dublin, Ireland). Both videos are on Youtube: bit.ly/1RwXOZb & bit.ly/1RwXOZc. If confirmed, this becomes the fifth such event in the past decade. For more info about old impact flashes see our previous post here. Click on the gif below to see a comparison side by side of the 2 videos with an apparent impact flash on the Jupiter's East limb. 
 

Credit: Kernbauer & McKeon


On March 03, 2016, delay-doppler images of asteroid 2016 DV1 were obtained using DSS-13 to transmit and GBT to receive. The images span ~1 rotation. Rotation period is about 304 +/-8 seconds.

Goldstone Radar Observations of 2016 DV1




















by Ernesto Guido

Wednesday, March 16, 2016

New Comet: C/2016 E2 (Kowalski)

CBET nr. 4266, issued on 2016, March 16, announces the discovery of a comet (magnitude ~18) by R. A. Kowalski on CCD images obtained with the 0.68-m Schmidt telescope in the course of the Catalina Sky Survey on Mar. 15.44-15.46 UT. The new comet has been designated C/2016 E2 (Kowalski).

We performed follow-up measurements of this object, while it was still on the neocp. Stacking of 65 unfiltered exposures, 15 seconds each, obtained remotely on 2016, March 16.3 from H06 (iTelescope network - New Mexico) through a 0.25-m f/3.4 reflector + CCD, shows that this object is a comet with a diffuse irregular coma nearly 10 arcsec in diameter.

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



M.P.E.C. 2016-F03  assigns the following preliminary parabolic orbital elements to comet C/2016 E2: T 2016 Feb. 6.70; e= 1.0; Peri. =  322.01; q = 1.07;  Incl.= 136.00

Credit: JPL

This comet will have a close approach with Earth at about 114 LD (Lunar Distances = ~384,000 kilometers) or 0.2920 AU (1 AU = ~150 million kilometers) on March 17, 2016 at 06:41 UT (it passed perihelion on Feb. 06, 2016 at 1.075 AU). Comet C/2016 E2 will fade in the coming days as its distance from both the Earth and Sun increase.


by Ernesto Guido & Nick Howes