ISON Image of the Week

Contributing Science (July 29, 2013)



The quality of this image of Comet ISON, taking in May 2013, belies its origin. It was taken with the 2m Liverpool Telescope on La Palma while under the control of Ernesto Guido and Nick Howes, two pro-amateur researchers collaborating with the Space Science Institute and Lunar and Planetary Institutes gathering data on comet ISON. Images like this exemplify the tremendously high-quality data that these astronomy programs and collaborations are now capable of producing. [Image credit: Ernesto Guido and Nick Howes.]
One of the many strengths of the Comet ISON Observing Campaign is how broad and inclusive it is. When our team was formed, our task was not just to coordinate and encourage all of the large, well-known observatories (i.e. Keck, etc) and spacecraft to observe and collectively gather science. Our task was to coordinate and encourage scientific observations from all resources have that capability. A few decades ago that really would have limited participation to just major observatories, but that's certainly no longer the case. "Amateur" astronomers (and we intentionally use quotes there) now have access to extremely large and powerful telescopes, and modern manufacturing of high quality optics now means that for only modest costs, anyone with the time, enthusiasm and clear skies can take extremely detailed and precise astronomical observations.

We recognized this early, and thus amateur participation is an important element of the CIOC, with astronomers Padma Yanamandra-Fisher and Elizabeth Warner taking the lead on our support of amateur observations. There's historical precedent for including amateur observations in observing campaigns, with Elizabeth's Amateur Observer's Program for example, which is based at the University of Maryland and was originally formulated for observations of Comet Tempel-1 during the NASA Deep Impact mission, but has continued on supporting other programs such as DAWN and EPOXI. It now is part of our CIOC, and contains great advice for amateur astronomers wishing to submit science-quality data.

It is important we clarify what we mean by "science-quality". Images of Comet ISON (or any comet) are always nice to look at, but when scientists see an image of a comet, the word that comes to mind is "data". Our goal is to extract useful information from those images so that we can apply scientific rules and methods to them. So what does that mean for images of Comet ISON? Well it means that we need not only the image (observation) but lots of information about it too. Where was it taken from? What was the exposure time? What are the details of the telescope? What is the telescope field of view? We also need image calibration information such as CCD bias and flat-field corrections. Again, Elizabeth's Amateur Observer's Program has an outstanding guide to image processing and calibration. Modern commercial and free astronomy software makes much of this very, very simple.

So what happens to the data that amateur astronomers record? The images can be used to study the morphology (shape) of the comet and its tail, the brightness of the comet, it's composition and dust production, and much more. A great example is a study orchestrated by Dr. Nalin Samarasinha from the Planetary Science Institute. He is spearheading a campaign to obtain images of Comet ISON from all over the world, and hopes to use those images to extract information about ISON's rotation, activity, gas/dust production, and more! Full details of his program are available in this 2.3Mb PDF. Any observations that Dr. Samarasinha ultimately uses in his study will be acknowledged with scientific publication co-authorship for the observers! This is all well within the reach of many amateur astronomers, and why the CIOC is so eager to include anyone who has the capability, time, and willingness to participate.

Every week this year we will put up a new image related to Comet C/2012 S1 (ISON). If you have a cool image you'd like us to consider, please send it to sungrazer@nrl.navy.mil, along with a description and any credits you would want applied. We'll contact you if we choose to use your image on the CIOC Website.

See our ISON Image of the Week Archives for earlier picks!