Comet ISON (C/2012 S1)

ISON’s dangerous journey towards the Sun:

Comet ISON as seen few hours after perihelion from NASA/ESA’s SOHO observatory (Nucleus of the comet is marked with yellow circle)


Brief History of Comet ISON :

Vitali Nevski (Belarus) and Artyom Novichonok (Russia) discovered a new Comet on 21st September 2012 using 16-inch telescope at International Scientific Optical Network (ISON).   Generally, comets are named after the discoverer/s however, this comet was discovered under the project ISON, the Comet was named as “Comet ISON” instead of naming it after two persons who spotted it first.

 Discovery image of ISON 

Discoverers of Comet ISON Vitali Nevski (Belarus) and Artyom Novichonok (Russia)

Pre-discovery observations:

Ironically, ISON was observed 17 times before it was discovered by Nevski and Novichonok.  In the images taken by Mount Lemmon Survey and PAN-STARR 1, this comet was visible.  The prediscovery observations of ISON are available in the Minor Planet Center’s (MPC) database.

At the time of discovery ISON was 6.294 Astronomical Units (the average distance between the Sun and the Earth) from the Sun, in other words, it was beyond the orbit of Jupiter.  Following diagram shows the position of ISON at the time of discovery:

Comet ISON is believed to have originated from Oort’s Cloud (a hypothetical huge reservoir of comets lying at a distance of about one light year from the Sun).  Unlike periodic comets, it is expected that this is ISON’s maiden travel to the Solar System.  Its orbit is a hyperbola, however it is expected to pass within 1.2 million kilometers from the surface of the Sun.  For this reason, ISON’s journey near the Sun is vital and may prove to be fatal.  However, current estimates based on the dimensions of ISON and the perihelion distance, experts believe that it will survive perihelion.

Perihelion date
November 28, 2013
Perihelion distance
0.012 AU
Inclination of its orbit to the ecliptic
62 degrees
Eccentricity of the orbit
Type of orbit
Observations of ISON:

ISON offered plenty of opportunities from ground as well as from space, as it was discovered more than one year before perihelion passage.  Hence, a wide range of observations are planned by many leading agencies.  NASA has opened Comet ISON Observation Campaign (CIOC) to observed ISON across various wavelengths.

Link to CIOC is here :

Eyes on ISON:

To observe Comet ISON, many Indian organizations too have come up and raised a nationwide expedition called ‘Eyes on ISON’.  The objective behind this expedition is to create awareness about comet to laymen and to cultivate scientific approach and culture.

Link to Eyes on ISON :


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