Prospects for Observing ISON

November and December 2013

By Bob Moler

What is a Comet?

The nucleus of Comet 103P/Hartley is 1.4 miles long.

Comets seem to come from the spherical that surrounds the solar system out to perhaps 1 light year.

The discoverers: Artyom Novichonok and Vitaly Nevski of the International Scientific Optical Network (ISON)

Path of the in-bound Comet ISON from the date of discovery, when it was still beyond the orbit of , to perihelion.

Path of the out-bound Comet ISON from perihelion out to Jupiter's orbit.

Comet ISON's describe the size and shape of it's orbit in 4 dimensions of space and time.

Light curve of predicted cometary brightness with actual magnitude measurements.

From Seiichi Yoshida's website: http://www.aerith.net/comet/catalog/2012S 1/2012S1.html

Comet ISON by Adam Block - October 8, 2013 - University of Arizona

The Path of Comet ISON November-December 2013

Comet 2P/Encke is in the same area of the sky with Comet ISON during November.

It is expected to be brighter than Comet ISON until November 19th.

Comet ISON is due to 'round the on November 28th, 2013

The path of Comet ISON through the field of view of SOHO's LASCO imagers

Let's take a look at the path of Comet ISON against the stars in an equatorial orientation like star charts show.

Track of Comet ISON from November 1st to the 7th

Track of Comet ISON from November 8th to the 14th

Track of Comet ISON from November 15th to the 21st

Track of Comet ISON from November 16th to the 28th

Track of Comet ISON from November 29th to December 4th

Track of Comet ISON from December 5th to the 11th

Track of Comet ISON from December 12th to the 25th

Track of Comet ISON from December 26th to January 8th

Let's take a look at the path of Comet ISON against the stars in an alt-azimuth orientation as you'd see it in the sky.

Track of Comet ISON from November 1st to the 14th

Track of Comet ISON from November 15th to the 28th

Track of Comet ISON from November 29th to December 19th

Track of Comet ISON from December 20th to January 9th

The big question for Comet ISON:

WillWill itit survivesurvive Perihelion?Perihelion?

Let's see some which didn't

Comet Shoemaker-Levy 9.passed close to Jupiter in July, 1992. Beside tearing the comet's nucleus into 22+ pieces, it altered the comet's orbit so these pieces would hit Jupiter 2 years later from July 16 through 22, 1994. The atmospheric blemishes lasted for months and were visible in small telescopes.

This comet began to break up in 1995 into 4 pieces. On its return in 2006 it came back in 8 pieces.

The Hubble made a multi-day movie of nucleus B breaking apart. Nucleus A didn't survive from 1995 and the intervening unseen passage of the sun between 1995 and 2006.

Comet C/2010 X1 Elenin discovered in December 2010 and disintegrated September 2012.

Let's look at 2 survivors, Comet McNaught of 7 years ago and Comet Lovejoy of 2 years ago

Comet McNaught C/2006 P1 (The of 2007) was best seen from earth's southern hemisphere

Photo from the SOHO LASCO C3 imager of Comet C/2011 W3 (Lovejoy)

Solar Dynamics Observatory image of Comet Lovejoy surviving it's encounter with the Sun's corona

The last to survive its close encounter with the sun – Comet Lovejoy in December 2011 – As seen from the International Space Station