(Extract) By Stefan Kürti (GRAS User)
Our story starts more than 400 years ago, when a new era in astronomy began under the watchful eyes of Galileo Galilei, who turned his telescope to the sky and began the first observations. As time went by, astronomers used more and more sophisticated instruments for observations, bigger and better scopes which were later joined by the advance of photography. Then 50 years ago we got the first direct images of the Moon and nearby planets transmitted to us by our first spacecrafts. And finally, in our modern times the first space telescopes began orbiting our planet. Hubble, Spitzer and WISE observatories enabled us to take a deeper look into the wonders of our universe than ever before.
But the real breakthrough in astronomical imagery came with the development of CCD cameras and broad usage of internet. The high power of this two instruments enabled amateurs with a medium setup to capture objects, which few years ago were privileges of only the biggest observatories and space telescopes.
Most of us marvel at seeing stunning photos of galaxies, nebulae or star clusters in books and magazines. However, these days images of comparable qualities pop up daily on various home pages of amateur astrophotographers worldwide. Browsing through these pages I came across the Global Rent a Scope (GRAS) website, where I found not only nice pictures but I also learned new words not very common in astronomical community until now – telescope time rental and remote observation.
Remote observation is a new phenomenon and most of us have certainly not heard about it. On the other side remote control is a well known word to everyone. We turn on and off the TV or DVD player using remote control without moving from our comfortable chairs. Orders given in one place are realized on somewhere else and it does not matter whether that place is few meters or thousand of kilometers away. Thanks to remote communication astronomers have now another tool in their hands to run observations. By great effort of few astronomy enthusiasts, observatories in remote locations were built, where conditions are almost ideal. Later, when fast and easily accessible internet allowed running telescopes without being physically next to them, only one more step remained towards starting renting out these automated observatories to the public.
We need a dark location to observe
To obtain high quality astro-images, apart from a decent setup, an observer needs a very dark sky. That is why many astrophotographers travel to remote sites around the world without any regret for spent time and money. Thanks to them we can read reports about astrophotography adventures, e.g. from Namibia or Chile. Unfortunately conditions in Central Europe are far from those experienced in magical places of Africa or other remote areas. Such excellent conditions, like almost no light pollution, low humidity, first-class seeing and lot of clear nights of locations 3000 meters above sea levels, are hard to find in the heart of Europe.
If you could however own a piece of land at those great locations, you would be able to realize your dream of setting up a smaller observatory. As it requires a rather big investment, it remains only a dream for many of us. But do not despair, there is solution. You can run observations from places with much better conditions than you find at your area. That someone, who was able to fulfill that beautiful dream of yours, already setup an observatory located in almost perfect places and allowed the rest of us to access it. And to use it, you will need just a fraction of the money you would need for constructing a complete observatory. To acquire your own beautiful images of deep sky wonders is therefore at your disposal.
Observation without your own telescope
Today’s modern technology has enabled us to observe the sky without owning a telescope or even being near to one. You do not need to drive far from your home, set up your telescope and make that tedious polar alignment only to realize that the sky just overcast. You are required to do only one thing, sit behind your computer and connect to internet. After preparing your observation plan in a simple text file, you send it over the telescope memory on the other side of Earth. The control software runs your order remotely. You can start your observation from the Spain, then when the Sun has risen there, continue from New Mexico and finish your imaging session from Down Under.
The control system of the remote telescope turns on the system at the time you selected, opens the roof of the dome, slews telescope to the star field you appointed, takes images for a desired time and then shuts down the observatory. When you return home from work, you only need to download new images via internet and you are ready for processing images and measuring them. Very convenient indeed!
The first so called internet remote telescope was launched in 2002. Since then several more of these remote observatories were established at different locations on Earth. In the following parts of this article I introduce one of these online observatories, which by enabling me to use their telescopes, helped me to reach a next step in my asteroid hunting hobby, e.g. observing under night sky.
Global Rent a Scope
Global Rent a Scope (GRAS) in Mayhill, New Mexico is the pioneering remote observatory who started their public service in 2002. When you decide to do remote observations, GRAS is a great choice as they offer the best choices not only because of wide range of remote telescopes but also for their various locations. You can observe both from northern (New Mexico, USA) and southern hemisphere (Australia). A third location in Spain as well. They have 13 remote telescopes to offer with various diameters and equipped with CCD cameras, 7 telescopes (pic 1) are in New Mexico and the rest in Australia. Another 2 will operate from Spain. The biggest instrument in Mayhill is 20“ Dall-Kirkham Cassegrain telescope, in Australia they have a wide choice and the two biggest scopes at 16”RCOS & 17”CDK. Minor Planet Centre (MPC) named GRAS Mayhill station as RAS Observatory with code H06 and Australian observatory E03.
You can search for variable stars, hunt for asteroids, follow new comets or just take photos of the objects of the starry sky by help of this well designed online observatory. You can make a reservation of observing time 120 days in advance, but you can also observe in real time when a selected telescope is free at that moment. You just sit behind your computer and the telescope thousands of kilometers away is taking images of your target object under the watchful eye of the Southern Cross. You would not be able to do that from your backyard (unless of course you live in the southern hemisphere).
Hunting the asteroids of the night sky
What could you achieve with 10“ telescope accompanied with SBIG-STXME10 CCD camera aimed at the dark sky over Mayhill? This question tempted me more than just to take some nice photos. For my first target I chose minor planet 2002 QB130. At a promising brightness of 19th magnitude it should have been an easy target for GRAS G4 telescope. Although its orbital elements were based on 2 oppositions, apart from the discovery in 2002, there were only few observations from 2004. Since then it was not observed for 5 years. To my surprise, I caught it on my second attempt. It was close to the expected position at 19.2m. I used exposures of 8 minutes and recording stars up to about 19.5 mag. Thanks to my new positions, the orbit of 2002 QB130 was improved well enough to allow MPC to link several other observations from the past. After that, my next step was obvious, to find a new minor planet on the night sky.
On January 2010, one week after full Moon, I exposed two search fields and finally on the second one accompanying few known asteroids, there appeared to be an unknown object. Next day I took some follow up images, where “my object“ moved (during 24 hours) as predicted, therefore I was able to find it easily.
GRAS - New Mexico - KurtiExcept that I discovered there another one. Then having obtained two nights’ positions I sent the results to MPC. As I did not receive any message from MPC, I checked both asteroids with MPChecker. Under the positions I measured there were two new asteroids, 2010 AB4 (pic 5) and 2010 AQ39. Suddenly, I became a discoverer! My next month was even better. I found another 4 new asteroids.
I managed to discovered another two asteroids, 2010 EM12 and 2010 EZ21. In May I turned to the southern sky as I was asked to observe minor planet 2007 YA4, which was about to be numbered, however it required additional and recent observations. After several failed attempts I finally caught it, but with it I captured another unknown object in the same field of view. Although for the following 8 days the weather forced me to stop observing, on 9th day I captured it again. My first minor planet from Down Under was named by MPC as 2010 JS152.
Astrophotographer´s dream
Keen astrophotographers do not mind travelling around the globe in order to observe deep sky objects, which they could not see from their backyard. However, travelling is not a necessity anymore as you can use on-line telescopes to get your astro-images. There are many different telescopes, CCD cameras and filters at your disposal, which offer an experienced astronomer-amateur a wide range of options to capture celestial objects. You can even discover new comets or asteroids while taking long exposure photos in combination with different filters. I am sure you heard about the Soap Bubble Nebula in Cygnus discovered last year by an amateur astronomer.
I consider myself to be an asteroid hunter rather than an astrophotographer, although I could not resist to take pictures of some objects found on southern sky. As a beginner, I decided to use the easiest way for astro-imaging, the so called „One-Shot Color“. From the GRAS list I chose the emission nebula NGC 3576 in Carina and the resulting 10 minutes exposure is shown in pic 4. It is not as captivating photo as those obtained by Hubble Space Telescope, but this is my own photograph.
Obstacles on the horizon?
A bad news came from MPC in April. The Minor Planet Center changed the rules of crediting new discoveries. Objects observed on two separate nights and linked by the discoverer are no longer given priority over discoveries made during 1 night and sent to MPC earlier. It meant that if you captured a new object and MPC could link it to an older single night observation, you would not be credited with the discovery. In other words it is becoming more and more difficult for amateurs to discover new asteroids. Only when you go deeper than most professional observatories and be ahead of them, you could succeed. But to compete with large surveys would mean using equipments out of reach of amateurs. This change disappointed me a great deal, however I hope that my discoveries just started and more will come.
Whether you want to image deep sky objects from southern sky or hunt for new asteroids, every remote observation require a thorough preparation. This means deciding where to aim the telescope, what exposure times to use, how many images to take, ways of calibration and stacking processes. It is not easy at all to find the optimal combination of all these steps to achieve the best results. You should also bear in mind the actual Moon phases and weather forecast. And of course, there is one other essential thing, the money. You are required to pay for the rental time. But remember, you are charged for your imaging only a small fraction of the total cost you would pay to build an observatory of similar quality in your backyard.
Remote observation surely does not offer you romantic moments of summer nights with falling stars, but the thrill of new discoveries or pleasures of captured beauty and wonder of the night sky remains the same.
Stefan Kürti
Monday, December 6, 2010 at 7:12AM 
During the past two years Norman Falla, based in suburban London, England has been using the GRAS telescopes in his search for new asteroids. To date his score amounts to two numbered-and-named plus another five awaiting further observations.
Currently the only survey that routinely detects asteroids significantly fainter than magnitude 22 is Pan STARRS in Hawaii. The first of four 1.8 m telescopes to be installed there is operational and can detect down to about magnitude 22.5. Although survey telescopes are generally much larger than the GRAS-011, 20” instrument and therefore potentially much more capable of detecting faint asteroids, they need to cover large areas of sky each night. They can only do this by reducing the exposure time per image and this reduces their magnitude limit.