Welcome toComet ISONC/2012 S1 (ISON)

S.PARTHASARATHYTamil Nadu Science Forum

In 1950, Jan Oort, worked on the distribution of comets in the solar systemIn 1950, he based on these dynamics of the long-period comets, concluded that the new long-period comets originate in a general cloud of comets surrounding the sun in a distance from 50,000 to 150,000 AU. This accumulation of comets which is called the Oort cloud is estimated to contain 1011 comets of observable size.

Origin of Comets Oort clouds(1950) *

In 1951, Gerard Peter Kuiper (student of Oort) suggested that a closer reservoir of comets lay just outside of the solar system, composed of the leftovers of the cloud from which our planetary system was formed.

He suggested that in a distance starting from the orbit of Neptune and extending as far as 50 AU a great population of comets is distributed in a flattened disk which acts as the source of the short period comets.

This distribution of comets, called the Kuiper belt, contains probably 107 to 109 comets larger than 5 km in size.Origin of Comets Kuiper (1951)*

Kuiper belt (total mass ~1/10 Earths) comets are believed to be remains of planetisimals, so they are where they were born, contains millions of different objectsKBOs. Best known example: Halley's comet (every 75 years). Oort cloud could contain billions of comets, most so small and distant as to never be observed, but ~3,200 long-period ones are known. These comets are believed to be born together with giant planets and pushed away by interactions. Best known example: Hale-Bopp, one of the brightest in 20th century.

Long-period comets come from Oort cloud; short-period from Kuiper belt.

Orbits

Comet ISON discoverers Artyom Novichonok (left) and Vitali Nevski On Sept. 21,2012 two amateur astronomers from Russia spotted what appeared to be a comet in images taken by a 16-inch (0.4-meter) telescope that is part of the worldwide International Scientific Optical Network, or ISON, from which the object draws its name.

C/2012 S1 (ISON)

Some example of magnitudes Mag What you need Examples -26 naked eye the Sun. -13 naked eye full moon. -6 naked eye crescent moon. -4 naked eye: easy even in large cities Venus. -2 naked eye Jupiter. -1 naked eye Sirius; Hale-Bopp near peak. 0 naked eye: difficult if near Vega; bright artificial lights, but generally Hyakutake at peak. visible even in large cities +1 naked eye: brilliant as seen Saturn. in dark, rural areas +2 naked eye: difficult but visible stars of Ursa Major; in small cities and suburbs, Halley's comet in diffuse objects like comets may 1986 near peak. require small binoculars in urban areas

ISON's Journey Towards Sun: Time Location Distance from Sun (AU)

10000years ago Oort cloud ~5500021 Sept 2012 Discovered 61 Dec 2012 Beyond the orbit of Jupiter 5.51 Jun 2013 Inside the orbit of Jupiter 3.5July-Aug 2013: @frost line 370-450 mln km from Sun 2.7 In July and part of Aug ISON was behind the Sun as seen from the Earth

1 Oct 2013 Close pass of Mars (10.8 mln km) 0 .0721 Nov 2013 Just inside Earth's orbit 0.9911 Nov 2013 Inside the orbit of Venus 0.723 Nov 2013 Inside the orbit of Mercury 0.328 Nov 2013 Perihelion (1.2 mln km from centre of Sun) 0.01226 Dec 2013 Closest approach to Earth (63 mln km) 0.429 On Jan 14- 15, 2014, after the comet itself has passed but when the Earth is sweeping near the comet's orbit, it might produce meteor shower.frost line of a system a line beyond which hydrogen compounds, like water, methane and ammonia would exist as ice. For our Solar System, this line is about 2.7 AU from the Sun roughly in the middle of the asteroid belt.

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200 (sun grazing) (Kreutz) . . 500-1000 .

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A sungrazer is like a solar probe Comets Lovejoy tail wriggling in solar invisible magnetic lines as a tracerSolar Terrestrial Relations Observatory (STEREO) EUV @17.1 nm (2011)

NASA's iconic Hubble Space Telescope has captured Comet ISON,

Observations

ObservationsSwift gamma-rays (Jan. 13)Deep Impact, HST (Jan-July)Spitzer in IR (June 13)Chandra in X-raysArecibo in radioFORTIS (Far-UV off Rowland Circle for Imaging and Spectroscopy)sounding rocket, 5-6 window (Nov 13)MRO (Mars Reconnaissance Orbiter), Curiosity and Opportunity optical (Aug 20th & Oct 13)Messenger probe optical (Nov 19th 13)SOHO, SDO and STEREO many wavelengths (Nov 13)

3.6 micron 4.5 micron dust CO gas

BalloonsIn September 2013 the window opens for balloons. The 1st balloon will be NASAs BRRISONIn November IIA high-altitude balloon group Blue will also launch a near-UV (200-400 nm window) spectrograph on a small balloon from IIAs CREST campus.

Magnitude 18.8

ISON on February 4, March 4, April 3, and May 4, 2013

Indian observationsStack of 6 images taken on 2-m HCT (Himalayan Chandra Observatory, Hanle) on 22nd Jan January 2013

February 2013 Stack of 6 images taken on HCT in I filter on 22nd Feb

Comets evolution22nd January-22nd February-1st May@740 mln km; tail ~64,400-km long ~@700 mln kmApr. 10th: @621 mln km; tail: 92,000-km long

Orbital position of C/2012 S1 on 11 December 2013 after perihelion

Path of comet C/2012 S1 (ISON) from December 2012 through October 2013 as it passes through Gemini, Cancer, and Leo

BACK ON JAN. 30, NASAS SWIFT SPACECRAFTAIMED ITS POWERFUL, MULTI-WAVELENGTH EYES AT THE COMET WHEN IT WAS STILL NEAR JUPITER. EVEN AT THAT DISTANCE, SOLAR HEATING VAPORIZED ENOUGH ICE FOR ISON TO SPEW OUT 112,000 LBS. (51000 KG) OF DUST A MINUTE.

On December 8, Comet ISON crosses into the northern sky. It should shine brighter than 1st magnitude and perhaps sport a spectacular tail. Northern Hemisphere viewers will get increasingly better views as Christmas approaches

Comet ISON and Mars November 1, 2013, just before Sunrise in the eastern sky (Northern Hemisphere). This occurs slightly after the long-standing ISON-Mars conjunction in earlier Leo.

November 12, 2013

November 18, 2013

Scenario in early morning sky before sunrise on 27th November13 Moon, Saturn, Mercury and Comet ISON

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It might eject vast jets of gas and dust and be spectacular with a fine tail and even become one of the finest comets.

Nov30 Dec 2 Dust tail may be visible in West after the sunset

(perihelion) , ? (size), (density), . 400 ( sun grazers) ( corona) , , SOHO STEREO . 1000 4000 . .

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Myths about ISON cometRecycled Nibiru idea (see www.cometisonnews.com)It has companions trailing it up to 7!It will as bright as the Sun (Moon is at -13, Sun is -26.74) Comet itself or particles from it could impact Earth (min dist to Earth will be ~63 mln km on Dec. 26th 2013)It could wreak a havoc on Earth with earthquakes, etc.It could cause a dangerous effect on the Sun - ?http://comet2012.com/bible-codes-comet-2012-s1-ison/Be prepared for Comet 2012 S1 (ISON)Comets are named in the Year in which they are found. Notice below that the word Comet always comes before 2012?. According to the Bible Codes this comet will either hit the earth or it will be destroyed by the sun.

Adam Block took this image of comet ISON using a SBIG STX16803 CCD Camera with a 32-inch Schulman Telescope Schulman Telescope atop Mount Lemmon from the University of Arizonas SkyCenter on the morning of Oct. 8

Acknowledgement

U.N.Deka, The Pragjyotish Amateur Astronomers' Association, AssamMargarita Safonova, Indian Institute of Astrophysics Bangalore

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***The Kuiper Belt extends from about 30 to 55 AU.****