Comet 17P/Holmes

Dr. Harold Williams

Montgomery College Planetarium

http://Montgomerycollege.edu/Departments/planet/

1892 image of Comet Holmes

What is know about the Comet

• Period of orbit around the sun, t=6.88 years, semi-major axis distance, s=3.617 AU, t2=s3 Kepler’s third law for the sun in years and AUs.

• Perihelion, p=2.053 AU, closest to the sun. Aphelion, a=5.18 AU, furthers to the sun, so eccentricity, e=(a-p)/(a+p)= 0.43241

• Last Perihelion date May 4, 2007, next perihelion date March 23, 2014.

• Ellipse Article in Wikipedia http://en.wikipedia.org/wiki/Ellipse

6 elements needed to define a ballistic free fall orbit around the

sun.The following orbital elements are taken from MPC 51822:

Epoch 2007 May 20.0 TT = JDT 2454240.5T 2007 May 4.4995 TT MPCq 2.053169 (2000.0) P Qn 0.1432508 Peri. 24.2585 +0.9756506 +0.1267918a 3.617468 Node 326.8675 -0.2124462 +0.7491399e 0.432429 Incl. 19.1132 +0.0545208 +0.6501640P 6.88From 139 observations 1964-2001, mean residual 0".7. Nongravitational parameters A1 = +0.19, A2 = +0.0287.

Wikipedia article on Apsis

What makes this comet so Special

Resent magnitude history

What astronomer use to find comets!

More detailed chart

Some useful Links

• Wikipedia Article http://en.wikipedia.org/wiki/Comet_Holmes

• Seiichi Yoshida (comet@aerith.net) http://www.aerith.net/comet/catalog/0017P/2007.html

• Solar System Dynamics JPL, Comet 17P/Holmes http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=17P;orb=1

• Gary W. Kronk’s Cometography http://www.cometography.com/pcomets/017p.html

Prettiest Image I have seen!

http://www.astro.umontreal.ca/~casca/PR/holmes_I.png

http://www.astro.umontreal.ca/~casca/PR/holmes_J.png