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Shoemaker Winner Hug Discovers Near Earth Asteroid 2013 AS27

Posted by Bruce Betts

10-01-2013 16:43 CST

Topics: Planetary Society Projects, Shoemaker NEO Grants, near-Earth asteroids, amateur astronomers, planetary astronomy

I heard from Planetary Society Shoemaker NEO grant winner Gary Hug in Kansas, USA that he discovered a new near Earth asteroid on Jan. 7.  I'll let him tell you about it in his own words, but first wanted to point out that although the Shoemaker grants are mostly designed to support the crucial orbit-defining follow-up observations of near Earth asteroids and characterization of them, the equipment provided has also continued to facilitate a fair number of discoveries even in this era of professional asteroid surveys.  Bob Holmes in Illinois, USA, another Shoemaker NEO grant winner, provided the first follow up to Hug's discovery.  This asteroid, designated 2013 AS27, is a big one at 140-310 meters, fortunately not on a near term collision course with Earth, but with close enough passes to Earth to lead to it being classed as a "Potentially Hazardous Asteroid (PHA)".  Thanks to Gary and Bob and all the other Shoemaker NEO winners and the Planetary Society members and donors who have supported them, our world is becoming a safer place from other worlds.  Now onto Gary's words:

"The Potentially Hazardous Asteroid 2013 AS27 was discovered Saturday night Jan 6th (7th U.T.) at Sandlot Observatory(H36) about 11:00 PM local time. It is the second NEO discovery at Sandlot Observatory in 4 months, the first being 2012 SY42, a Virtual Impactor discovered in September 23rd, 2012.

Gary Hug Discovery Images for Near Earth Asteroid 2013 AS27

Gary Hug

Gary Hug Discovery Images for Near Earth Asteroid 2013 AS27
On January 7, 2013, Gary Hug discovered near Earth asteroid 2013 AS27 using the new capabilities from a Planetary Society Shoemaker grant provided camera. These two cycling images, taken 13 minutes apart, show the asteroid moving relative to the background stars. Note that there are also "blinking" pixels in the same region that just represent pixel noise, probably from cosmic ray hits in the detector during one image or the other.

2013 AS27 was picked up while searching for another object listed on the NEOCP page. Once again because of the wide field of view of the SBIG STL1001E CCD camera afforded by a Shoemaker NEO Grant from the Planetary Society, the 18th magnitude object was noticed near the west edge of the field traveling at about 8-9 arc-secs per minute. It was too slow for most satellites but moving about 10 times faster than most main belt asteroids. I checked to see if it was a known object and when verified, I ran the astrometric analysis and turned in the data to the MPC (Minor Planet Center). Within 10-15 minutes lb4020 (my temporary designation) was listed on the NEOCP (Near Earth Object Confirmation Page) at the MPC. A few hours passed before Bob Holmes of ARI (another Shoemaker NEO Grant recipient) swept up the object and turned in follow-up data. During the next 30 hours a dozen other observatories around the world contributed observations and this morning (Jan 8th) the MPC issued an electronic circular (MPEC 2013-A42).

2013 AS27 can get as close as .034 astronomical units to the Earth. ( 1 A. U. = the average distance from the Earth to the Sun.) The H value is listed as 21.4 meaning it's likely to 140 to 310 meters wide. The combination of its mass and potential close proximity to the Earth make it an object of interest. There is no present concern, however, as it passed at a safe 10 million miles this time around."

See other posts from January 2013


Or read more blog entries about: Planetary Society Projects, Shoemaker NEO Grants, near-Earth asteroids, amateur astronomers, planetary astronomy


Bob Ware: 01/13/2013 08:40 CST

Gary - Congratulations!! I'm glad you found it but it is a double edge sword knowing the PHA's have just increased. Looking from a science view point this is awesome! An asteroid that will pass close enough to catch it some day? Any measurement on the orbit yet?

Bob Ware: 01/13/2013 09:09 CST

One question: I'm confused on the designator for this asteroid. Why isn't it 2013AB sub 1 or 2013A01B? That is, as I understand the nomenclature, B sub1 equals 27. Right? No? Thanks.

Gary Hug: 01/14/2013 02:51 CST

Hi Bob, They can go deep into the hundreds. (ie.. 2013 AS134 or even AS331 is a possibility). It only becomes a problem when using what is known as the 'packed form'. Then 2013 AS27 becomes K13A27S. But 2013 AS134 becomes K13AD4S. where a single letter is used to describe the 1st two digits. In this case the 'D' fills in for the 13 of 134 A=10 B=11 C=12 D=13 E=14 ......and so on More info is online at the MPC Hope this is of some help, cheers Gary

Bob Ware: 01/14/2013 05:43 CST

Hi Gary - Thanks. I appreciate it. I believe I have it understood. Thanks again and again congrats on the great find!

Jim Bergquist: 01/15/2013 05:24 CST

There is a small fuzzy object at pixel coordinates 679, 595 in the original image that appears to be moving slowly left and right. It doesn't look like it's just pixel noise.

Emily Lakdawalla: 01/15/2013 10:37 CST

Yep, that's a (known) main-belt asteroid. Gary said that apart from that one, there's a few others in the discovery images that are harder to spot.

sixes: 01/20/2013 12:50 CST

what do you mean known main belt asteroid.

Emily Lakdawalla: 01/21/2013 04:38 CST

An asteroid in the main belt of asteroids between Mars and Jupiter that had previously been discovered by another astronomer at another time in the past.

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