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Comet C/2012 S1 (ISON)

A comprehensive set of Hubble Space Telescope (HST) observations of Comet ISON has been approved, with some early programs already executed.

IDProposal TypeScience InstrumentPIepoch
13197DDSTISA'Hearn2 May 2013
13198DDWFC3Li10 Apr 2013
13199DDACSHines7 May 2013
13229 DDWFC3Levay30 April, 8 May 2013, 9 Oct 2013, more TBD

On July 16, 2013 the STScI Office of Public Outreach released a blog ( to gather inf ormation about HST observations of Comet ISON together.

Hubble Heritage program 13229 imaged the comet on 8 May 2013, using a Wide Field Camera 3 (WFC3) subarray which is half of one of the two CCDs (2K x 2K subarray). Eight identical 171-second exposures were obtained, with one dither step to mitigate bad pixels. The long-pass F350LP filter was used to maximize the signal-to-noise in one orbit. A small offset from the nominal aperture was applied to optimally position the comet and tail within the field of view.

Comet ISON Blog - December 20,2013
Hubble Heritage Release - Nov 18 2013

Another orbit on 30 April 2013 obtained deep fixed-pointing images of a field with Comet ISON in it, released July 16, 2013. Further details about the Heritage Comet ISON observing program are contained in the Phase II observing program.

Observations on Oct 9, 2013 showed the comet was intact. The press release was released October 17, 2013. The data were taken in two filters and the HLSP were released Oct ?? 2013

On December 18, 2013, HST tried to observe Comet ISON one last time. There was no evidence of Comet ISON in these images. Please see details about the observations and conclusions in the Comet ISON blog.

the Data
Release DateExplore the image
13229DataJune 27, 2013Interactive Display
13229DataJuly 16, 2013Interactive Display
13229DataOctober 9, 2013Interactive Display
13229DataNovember 2, 2013Interactive Display
13229DataDecember 18, 2013Interactive Display