Bob Holmes Discovers a Trans-Neptunian Object
A little while ago, in mid April, EIU Adjunct professor Bob Holmes was going about his routine work searching for near-Earth objects and recording data on their orbits. That night he was measuring the current location of a near-Earth object named 2009 OB3 when Bob Holmes saw something else in his data that was highly unusual. It was another faint object that was moving very slowly relative to the stars. That meant that it was likely orbiting the Sun at very great distance. Upon further investigation he had discovered it to be a very large distant asteroid that was given the provisional designation 2012 HH2 by the Minor Planet Center in Cambridge, MA. The new discovery would be a trans-Neptunian object about 200km in diameter and currently resides at a distance farther than Pluto. It has a period of 232 years and varies in its orbit from 29.5 AU to 46 AU from the Sun. An AU is the distance from the Sun to the Earth. Don’t bother looking for this new object in the sky because it can’t be seen with the naked eye. It takes a pretty good telescope and knowing exactly where to look as the discovery was made at unfiltered magnitude 21.6 or about 3 million times fainter than your eye can see.
This is exciting enough to gather interest from other observatories around the world. It only took a few nights before there was confirmation of the existence and location of the new discovery. Some follow-up measurements from the Catalina Sky Survey (Tucson, AZ) and the Magdalena Ridge Observatory (Socorro, NM) were important in helping to determine the orbit and establish that 2012 HH2 resides in the outer Solar System.
Below is a diagram showing the orbits of the planets, Pluto, and 2012 HH2.
Bob doesn’t generally look at objects that are beyond Neptune. So he was amazed when he ran the statistics on this object and produced the attached diagram of the asteroid orbit.
Bob is pleased to discover this object as it is one of the most distant objects that have ever been discovered within our solar system. He has found asteroids and comets over the years and recently named an asteroid in honor of EIU professor and long time colleague Dr. James Conwell. Bob joked that all he has left to discover is a planet. Sorry, Bob, they are all taken and we really don’t expect to find any more.
For the true Astronomy geek we offer the statistical details of this discovery.
Perihelion 2012 Apr 16.459423 TT = 11:01:34 (JD 2456033.959423)
Epoch 2012 Apr 20.0 TT = JDT 2456037.5 Ne: 0.7768 Find_Orb
M 0.01501 (2000.0) P Q
n 0.00424197 Peri. 131.40307 -0.91005155 0.12747009
a 37.7941058 Node 59.58547 -0.34990967 -0.74633763
e 0.2198477 Incl. 27.21593 0.22219223 -0.65324690
P 232.35 H 6.4 U 11.3 q 29.4851568 Q 46.1030548
From 12 observations 2012 Apr. 19-21; mean residual 0".147.