Date:May 4, 2011
Title: A Tale of Two Comets
Podcaster: Nick Howes
Links: Faulkes Telescope Project
Description: Comet C/2007 Q3 (Siding Spring) was discovered by Donna Burton in 1986.
During the course of its last opposition, amateur astronomer Nick Howes using the 2m Faulkes Telescope in Hawaii along with professional observatories in France and Italy independently and simultaneously detected a significant break up in the comet nucleus. The resultant global media attention and further observations of both this comet and Comet 103P Hartley, where Howes independently calculated the comet rotation speed using rotational gradient processing in commercial software show that professional/amateur collaborations are still important in the field of astronomy, and how, by using amateurs with their unlimited telescope time as the driving force behind projects, outreach and education gains an interface to the world of high end astronomy.
Bio: Nick Howes works for a UK firm as a Test Analyst. Whilst his day job and family consume most of his time, he also finds a way to squeeze in writing as a freelance journalist for Astronomy Now where he regularly reviews and tests CCD cameras and telescopes, as well as writing about interesting historical locations for Astronomy around the world. Nick has also written for Amateur Astronomy and Practical Astronomer magazines. His passion in astronomy is imaging the Sun, using a collection of narrowband solar telescopes, and also deep sky imaging using a parallel mounted refractor setup from his home observatory in Wiltshire, where he is a member of Wiltshire Astronomical Society. He is currently working on comet recovery programs and with ESO on imaging massive star clusters
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Transcript:
It all started in March 2010, when I was online on the UK’s Stargazers lounge astronomy forum. One of the members, of which there are now over 13,000 had mentioned that comet C/2007 Q3 was approaching an edge on galaxy NGC5907 in the constellation of Draco. As a keen astro imager, and someone who really enjoys in particular imaging comets, this looked like an opportunity not to be missed. Sadly, on the night in question, the UK weather played its usual tricks, and clouded me out, but on the two following nights, all was clear, with really good seeing, so I decided to follow this comet anyway. Imaging it with my TMB105mm refractor and Atik 314 CCD camera using a broadband clear sky light pollution filter, over the course of two nights I noticed that the comet significantly brightened. Thinking this somewhat odd, as no reports of the comet going in to outburst were being reported on any of the forums, and with a call from the BAA’s Callum Potter to image the comet in more detail, I decided to use some of my allocated time on the 2m Faulkes Telescope in Hawaii to image the comet at much higher resolution. The Faulkes telescope project is an educational one set up by Dill Faulkes, a UK based entrepreneur, who invested around $17,000,000 into setting up two 2m telescopes, one in Hawaii, and one in Siding Spring, Australia. These scopes, armed with sensitive CCD cameras are aimed at not only professional research, but also at encouraging school children in to astronomy. They have web accessible interfaces, which are very simple and intuitive to use, and come armed with a wide range of filters from the basic LRGB types, through the entire Hubble palette of narrowband filters, and the Sloan Digital Sky survey ones. As a scope, it’s 2m mirror enables not only sub arc-second resolution in imaging, but also the ability to image very faint and deep objects very quickly.
I use the Calsky.com website to obtain coordinates of objects I am imaging most nights. As my main focus for the past year or so has been comets, it’s a handy resource, as it enables you to set observing locations easily for anywhere on the globe, and I have setup three accounts for home, and the two Faulkes scope locations. This takes its data feed for comets positions from the Harvard minor planet centre, but puts it across in, to my mind anyway, a more user friendly format. Comet C/2007 Q3’s coordinates and real motion meant that images of around 20s would be sufficient to capture the coma, but, as the Faulkes setup only has a 4.7 arcminute field of view, not the, by now extensive tails which extended from it.
Comet Siding Spring with its official designation of C/2007 Q3, was discovered by Donna Burton, a researcher who at the Siding Spring Observatory in New South Wales, Australia. As she had discovered the comet, but sadly was unable to make a follow on observation, the comet was not named after her, but after the observatory, to my mind, still something which should be changed by the MPC. The comet itself has an orbital period calculated at around 650,000 years and came within 1.2 astronomical units of Earth and 2.25 AU of the Sun in Oct 2009 2009.
My imaging session on Faulkes (and these are typically in 30 minute slots) was booked for the Tuesday after my weekend session where I’d notived the tail brightening. At the same time, another amateur astronomer, John Slinn, who was at the Isle of Wight Star Party, had also imaged the comet, and also noticed a brightening, but this fact only came to light after what turned out to be one of the most memorable days of my life.
The imaging run began as ever with the Faulkes scope slewing to the target, and me setting up the filters. Usually for comets I use either the Sloan R band filter or photometric V band filters. Faulkes when the image is taken, then takes around 50 seconds to download and prepare the image, doing automatic dark and flat field subtraction, before presenting a preview in jpeg form of the object imaged. The jpeg appears in your web browser, and then a few minutes later, you have access to the raw FITS file data via the LCOGT (Las Cumbres Observatory Global Telescope network, who now manage the Faulkes scopes). The FITS data can be downloaded one at a time, or in a batch, and it was the one at a time approach I was using so that I could get to work quickly on this target. Bearing in mind, I have a full time day job as a test engineer, these Faulkes runs usually take place during my lunch hour, so I have to work quickly to get the data reduced and astrometry etc submitted.
The first image came through, and I opened it up in Maxim DL, which is my preferred image processing application, and after a quick stretch of the histogram, it became blindingly obvious that something was not quite right. Just behind the comet, there was a smaller fuzzy blob, probably around magnitude 15 from initial estimation, and separated from the main coma/nucleus region by only 3-4 arcseconds. The second image came in, and by this time the comet had moved against the star background, but this small fuzzy blob was moving with the comet, in the same direction. In total I managed to get 12 images of the comet during my 30 minute run, and the blob tracked the comet perfectly. At this point the adrenalin started to kick in. Nothing like this had happened to me before. Again, I went online onto the various comet newslists and forums, but nothing had been reported. I phoned up Andy Burns at Wiltshire astronomical society, a seasoned observer and asked his advice, he recommended I contact Faulkes headquarters immediately, and notify them, followed by the BAA comet section. Frantic phone calls ensued, with Faulkes almost immediately putting up a press release on their website. The BAA comet section, after sending images to demonstrate what I thought I had found, also put up a notice on their discoveries page, and then, quite literally all hell broke loose. I also contacted friends at Caltech, after having visited Mt Palomar the year before to see if they could image the comet in even more detail.
Apart from my day job as a software and hardware test engineer, I am also the equipment consultant for the UK’s Astronomy Now magazine. I contacted their editor who put me in touch with their website editor, Dr Emily Baldwin, herself a PhD in solar system impacts. She took notes via email and over the phone, and broke the story to the world via the Astronomy Now website. Faulkes Telescope were also putting out press releases to the wider media, as, whilst not uncommon, these fragmentation events are still notable and for an amateur using a robotic scope to detect one, quite rare. From that moment on, my phone literally didn’t stop ringing for almost two weeks. Everywhere from Hawaii, the Canada, the USA, Ethiopia, continental Europe, Australia and the British press, including the BBC and several national newspapers wanted the story of “the office worker who’d made a major astronomical discovery”. Radio stations from around the world wanted to speak to me, Discovery Channel in Canada featured it on their news reports, and the BBC’s Sky at Night television show covered it in their monthly news items. The fragment which had come off, was estimated to be around the size of Mount Everest, and had, in fact been detected and imaged by a group in Italy as well as the Pic Du Midi observatory in France, but neither of them had put up their results, leaving me with a lot of the credit, even though it was, and I openly acknowledge this a co-discovery.
Astronomy Now updated their breaking news story and I conducted a video interview with them to talk more about it. Ongoing observations showed the fragment was slowly drifting away from the main nucleus. I continued to observe and image it for over a month, along with many other professional and amateur observatories around the world. Faulkes telescope recorded a 4000% increase in website activity as a result of this event, and it spurred me on to do more imaging of these mysterious interlopers.
Then, later in 2010, another comet appeared on my radar, 103P Hartley. This was going to be blanket covered by the media due to a flyby event scheduled with the NASA Expoxi mission. EPOXI was an extended mission that utilized the already “in flight” Deep Impact spacecraft to explore distinct celestial targets of opportunity. The name EPOXI itself is a combination of the names for the two extended mission components: the extrasolar planet observations, called Extrasolar Planet Observations and Characterization (EPOCh), and the flyby of comet Hartley 2, called the Deep Impact Extended Investigation (DIXI). This spacecraft was scheduled to make a close approach of the comet, taking high resolution images of the nucleus to augment the already impressive sets of images taken by craft like the Hubble Space Telescope. Managed by an investigation team based at the University of Maryland, this comet was interesting in that it was only the 6th mission in history to do a close approach of a cometary body. The EPOXI team had set up a Facebook page for people to join who were interested in monitoring this mission. As I was imaging the comet, I joined, and quickly became friends with one of the people managing their public outreach program, Elizabeth Warner, based at the University. She told me that they were running an amateur observing program, and that I should post up my images of the comet to that, which, I duly did on a day by day basis, both from my own observatory images, and also from the Faulkes high resolution imaging I was doing,
By this point, I had also been invited to join the Italian CARA (Comet
Research) group, and we were coordinating our efforts in an attempt to get some real science data into this project. One area of interest for me in particular was determination of the comet’s rotation rate.
Hubble images had estimated somewhere in the region of around 18-19 hours for the rotation speed, but I was determined to try an get a more accurate value on this. Using a campaign which involved not only my own images, but also those taken by schools using Faulkes over a period of several days, and using rotational gradient processing on the comet’s inner coma region, I calculated that the rotation rate was closer to 17 hours, and posted this result up onto the Facebook page. After the NASA team did more analysis, this value turned out to be remarkably accurate. I was taking lots of images of the comet ahead of close approach from home, and posting them to the NASA site. Here, it seems again, the press literally latched on to my results, and I was deluged in requests to use my images of the comet, by such prestigious publications and media outlets as National Geographic, MSNBC and again, the Discovery Channel. NASA even used one of my images at their press conference at JPL alongside images taken with the Hubble.
As a result of all of this, I am now conducting more research into comets, looking at reasons why they fragment, and taking part in an ongoing comet recovery and detection project using Faulkes Telescopes.
It’s been a whirlwind year, one that I don’t think I will ever forget, and one which hopefully will inspire many others to not only take pretty pictures of the sky, but also look and see what’s in those images, as you never know, a new comet discovery could be just around the corner and it could be you.
End of podcast:
365 Days of Astronomy
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