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 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.
Asteroid 2012 DA14 had a close approach with Earth at 1925 UT on 2013 Feb. 15. at about 0.09 LD (Lunar Distances = ~384,000 kilometers) or 0.0002 AU (1 AU = ~150 million kilometers). For more info about this asteroid and its close approach see our previous post.
Below you can find a selection (in chronological order) of our images & animations taken before, during and after the close approach.
Image of 2012 DA14 taken remotely from Australia on February 15, 2013 at 17:40UT. Exposure time 5 seconds with a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer from Q62 (iTelescope Observatory, Siding Spring). The asteroid was then of magnitude ~9.5 and moving at ~1140 "/min and less than 2 hours before its close approach of 19:25UT. Click on the image for a bigger version.
Below you can see a short animation made by using 3x5-second exposures. Click on the thumbnail for a bigger version.
Image taken remotely from Australia on February 15, 2013 at 18:45UT, just 40 minutes before the close approach. Exposure time 60 seconds with a 0.1m f/5.0 Astrograph + CCD from Q62 (iTelescope Observatory, Siding Spring). The asteroid was then of magnitude ~7.6 and moving at ~2665 "/min.
Credit: E. Guido & N. Howes
Image taken from Remanzacco Observatory in Italy (mpc code 473) on February 15, 2013 at 20:54UT. Exposure time 20 seconds. The asteroid was then of magnitude ~8.2 and moving at ~1513 "/min. Observers L. Donato; D. Lasaponara; G. Pasqualin; V. Santini; M. Travagini.
Credit: L. Donato; D. Lasaponara; G. Pasqualin; V. Santini; M. Travagini
Image taken remotely from Spain on February 15, 2013 at 22:31UT, 3 hours after the close approach. Exposure time 60 seconds with a 0.15-m f/7.3 refractor + CCD from I89 (iTelescope Observatory, Nerpio, Spain). The asteroid was then of magnitude ~9.9 and moving at ~525 "/min. Click on the image for a bigger version.
Credit: E. Guido & N. Howes
Below you can see a short animation made by using 2x60-second exposures. Click on the thumbnail for a bigger version.
Image taken remotely from New Mexico on February 16, 2013 at 11:47UT, roughly 16 hours after the close approach. Exposure time 10 seconds with a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer from H06 (iTelescope Observatory, New Mexico). The asteroid was then of magnitude ~9.9 and moving at ~525 "/min. Click on the image for a bigger version.
Credit: E. Guido & N. Howes
Below you can see a short animation made by using 14x10-second exposures. Click on the thumbnail for a bigger version.
2012 DA14 has an estimated size of 40 m - 90 m (based on the object's absolute magnitude H=24.09) and it will have a close approach with Earth at about 0.09 LD (Lunar Distances = ~384,000 kilometers) or 0.0002 AU (1 AU = ~150 million kilometers) at 1925 UT on 2013 Feb. 15.
2012 DA14 will pass only ~ 27,700 km (17,200 mi) above the Earth's surface, that is only 0.09 lunar distances or 5.4 Earth radii from the center of the Earth. So close that it will pass inside the ring of geosynchronous weather and communications satellites (located about 35,800 kilometers (22,200 miles) above the equator, but still well above the vast majority of satellites, including the International Space Station). Due to the extremely close approach, this object will be a very strong radar target at Goldstone where observations are scheduled on 2013 Feb. 16, 18, 19, and 20. Radar images should provide constraints on the size, shape, and rotation state of the object.
Credit: NASA/JPL Near-Earth Object Program Office
This asteroid will reach the peak magnitude ~7 on February 15 around 1930 UT and it will be brighter than 9th magnitude for approximately 3 hours (18h00-21h30 UTC). At the moment of the close approach 2012 DA14 will move at ~ 2800"/min (slightly less that 1 degree per minute). This means it will need only 40 seconds to move the apparent diameter of the Moon. While it will be too faint to be seen with the naked eye, 2012 DA14 will be easily visible with a good set of binoculars or a small telescope. It will rise above the horizon in the constellation Virgo, after that it will move in the direction of the north celestial pole, reaching about 10th magnitude approximately two hours later in the Little Dipper. In the morning hours of February 16, it will have crossed half of the sky, moving slowly close to the Pole Star at a magnitude of 13.
Below you can see an animation (10-minute steps) showing the path of 2012 DA14 from 21:00 UT of Feb. 15 to 02:00 UT of Feb. 16 (calculated for Rome, Italy). Next to the asteroid designation, you can see the expected magnitude value. Click on the animation for a bigger version.
The animated gif below made by Geert Barentsen indicate (green areas) parts of the world where the asteroid will be above (and the Sun below) the horizon during the period of its maximum brigthness (18h00-21h30 UTC of Feb. 15). Observers in Australia, Asia and Europe will be best placed. Click on the animation for a bigger version.
While there is no cause for concern ( 2012 DA14 will NOT impact Earth), this is one of the closest approaches recorded and the record close approach for a known object of this size. The table below shows the top 20 closest approaches by NEOs (Near-Earth Objects) sorted by nominal distance (click on the image for a bigger version).
Credit: NASA/JPL
While the table below shows the top 20 closest approaches by NEOs (Near-Earth Objects) sorted by nominal distance + absolute magnitude H < =26. (click on the image for a bigger version).
Credit: NASA/JPL
According to JPL website"on average, we expect an object of this size to get this close to the Earth about once every 40 years. An actual Earth collision by an object of this size would be expected much less frequently, about once every 1200 years on average".
We plan to image 2012 DA14 during its close approach so stay tuned!
UPDATE - February 14, 2013
Below you can see a short animation showing the motion of asteroid 2012 DA14 on Feb. 14, 2013 at around 11:06UT. The asteroid was moving at ~1.15 "/min and its magnitude was ~17. The animation has been assembled using 3 images taken with Faulkes Telescope South 2.0-m f/10.0 Ritchey-Chretien + CCD operated by Las Cumbres Observatory Global Telescope Network by E. Gomez. Animation by Remanzacco Observatory.Click here or on the animation for a bigger version.
(Credit LCOGT/Faulkes)
UPDATE - February 15, 2013 - 11:00UT
Apparently, at about 09:30 local time, a very big meteor burned up over Chelyabinsk, a city in Russia just east of the Ural mountains, and about 1500 kilometers east of Moscow. A pretty big sonic boom from the fireball, which set off car alarms and shattered windows. There are reports of many people injured (by shattered glass blown out by the shock wave).
According to ESA expertsthere is NO link between Russia event & asteroid 2012 DA14 close approach.
Here you can see preliminary calculations showing how the 2 events are unrelated.
UPDATE - February 15, 2013 - 20:00UT
We have been able to image 2012 DA14 remotely from Australia on February 15, 2013 at 17:40UT. Exposure time 5 seconds with a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer from Q62 (iTelescope Observatory, Siding Spring). The asteroid was then of magnitude ~9.5 and moving at ~1140 "/min and less than 2 hours before its close approach of 19:25UT. Click on the image for a bigger version.
Credit: E. Guido & N. Howes
Below you can see a short animation made by using 3x5-second exposures. Click on the thumbnail for a bigger version.
UPDATE - February 15, 2013 - 22:00UT
New image we have obtained remotely from Australiaon February 15, 2013 at 18:45UT, just 40 minutes before the close approach. Exposure time 60 seconds with a 0.1m f/5.0 Astrograph + CCD from Q62 (iTelescope
Observatory, Siding Spring). The asteroid was then of magnitude ~7.6
and moving at ~2665 "/min.
Credit: E. Guido & N. Howes
UPDATE - February 16, 2013 - 13:00UT
You can find here a selection (in chronological order) of our images & animations taken before, during and after the close approach.
UPDATE - February 19, 2013 - 19:00UT
An initial sequence of radar images of asteroid 2012 DA14 was obtained on the night of Feb. 15/16, 2013, by NASA scientists using the 230-foot (70-meter) Deep Space Network antenna at Goldstone, Calif. Each of the 72 frames required 320 seconds of data collection by the Goldstone radar.
The observations were made as the asteroid was moving away from Earth.
The asteroid's distance from the radar dish increased from 74,000 miles
(120,000 kilometers) to 195,000 miles (314,000 kilometers). The
resolution is 13 feet (four meters) per pixel. The images span close to
eight hours and clearly show an elongated object undergoing roughly one
full rotation.
M.P.E.C. 2012-X37, issued on 2012 Dec. 9, reports the discovery of the asteroid 2012 XE54 (discovery magnitude 17.3) by Catalina Sky Survey (mpc code 703) on images taken on December 09.1 with a 0.68-m Schmidt + CCD.
2012 XE54 has an estimated size of 20 m - 44 m (based on the object's absolute magnitude H=25.6) and it will have a close approach with Earth at about 0.6 LD (Lunar Distances = ~384,000 kilometers) or 0.0015 AU (1 AU = ~150 million kilometers) at 1004 UT on Dec. 11 2012. This asteroid will reach the peak magnitude ~13.0 on December 11 around 0600 UT.
We performed some follow-up measurements of this object, from the H06 ITelescope network (near Mayhill, NM) on 2012, Dec. 11.3, through a 0.25-m f/3.4 reflector + CCD. Below you can see our image, single 60-second exposure, taken with the asteroid at magnitude ~13.2 and moving at ~630 "/min. The asteroid is trailed in the image due to its fast speed. At the moment of the close approach 2012 XE54 will move at ~ 720"/min. Click on the image below to see a bigger version. North is up, East is to the left.
Below you can see a short animation showing the movement of 2012 XE54
(three consecutive 60-second exposures). North is up, East is to the
left. Click on the thumbnail for a bigger version:
According to calculations made on December 10 by P. Tricarico, 2012 XE54 "will likely cross the Earth's shadow, causing a partial eclipse of the asteroid a few hours before reaching its minimum distance with the Earth. Asteroids eclipsing during an Earth flyby are relatively rare, with the first known case of asteroid 2008 TC3 which was totally eclipsed just one hour before entering Earth's atmosphere over Sudan in 2008, and asteroid 2012 KT42 experiencing both an eclipse and a transit during the same Earth flyby in 2012".
The plot below shows the expected average apparent magnitude of asteroid 2012 XE54 (line), the filter-corrected magnitudes reported (blue boxes) and the dip due to the eclipse (red curve).
Credit: Pasquale Tricarico, 2012
This prediction has been confirmed by observations made by Peter Birtwhistle(J95 mpc code). Peter put up a very preliminary lightcurve (see graph below) covering the eclipse earlier today, showing minimum centred around approx. 01:37:00 UT, probably around mag ~ +17.5.
Credit: Peter Birtwhistle, 2012
by Ernesto Guido & Nick Howes in memory of our dear friend & colleague Giovanni Sostero
