1. Comet 17P/Holmes Dr. Harold Williams Montgomery College Planetarium http://Montgomerycollege.edu/Departments/planet/

2. 1892 image of Comet Holmes

3. What is know about the Comet Period of orbit around the sun, t=6.88 years, semi- major axis distance, s=3.617 AU, t 2 =s 3 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 http://en.wikipedia.org/wiki/Ellipse

4. 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 2454240.5 T 2007 May 4.4995 TT MPC q 2.053169 (2000.0) P Q n 0.1432508 Peri. 24.2585 +0.9756506 +0.1267918 a 3.617468 Node 326.8675 -0.2124462 +0.7491399 e 0.432429 Incl. 19.1132 +0.0545208 +0.6501640 P 6.88 From 139 observations 1964-2001, mean residual 0".7. Nongravitational parameters A1 = +0.19, A2 = +0.0287.

5. Wikipedia article on Apsis

6. What makes this comet so Special

7. Resent magnitude history

8. What astronomer use to find comets!

9. More detailed chart

10. Some useful Links Wikipedia Article http://en.wikipedia.org/wiki/Comet_Holmes http://en.wikipedia.org/wiki/Comet_Holmes Seiichi Yoshida (comet@aerith.net) http://www.aerith.net/comet/catalog/0017P/2007.h tml http://www.aerith.net/comet/catalog/0017P/2007.h tml Solar System Dynamics JPL, Comet 17P/Holmes http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=17P;orb=1 http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=17P;orb=1 Gary W. Kronk’s Cometography http://www.cometography.com/pcomets/017p.html http://www.cometography.com/pcomets/017p.html

11. Prettiest Image I have seen!

12. http://www.astro.umontreal.ca/~casc a/PR/holmes_I.png

13. http://www.astro.umontreal.ca/~casc a/PR/holmes_J.png