The Big Bear Conference 2006
Harry Colvin
Well, no, this was not a conference about big bears, but something just as exciting. Its real name is the Annual Conference of the Society for Astronomical Sciences. The sole purpose of this society is the promotion of research collaboration between amateurs and professional astronomers. The conference was held at the Northwoods Resort in Big Bear Lake, California, about 100 miles northeast of Ontario, in the scenic San Bernadino Mountains. I have been a member of the Society for several years, but had never attended the conference. With my galaxy clusters imaging project due to end in the next several months, I was looking around for new astronomy adventures. And I hit the jackpot with this group.
Wow, three days of non-stop science presentations by amateur and professional astronomers from around the world, describing the results of their collaborative efforts. The activities did not stop at 5:00 p.m., as discussions continued until late into the night in hospitality rooms where one got a chance to meet research leaders over a glass of wine or stronger spirits. This is where the pros recruit the best amateurs they can find; those with private observatories, equipment, and most important— the interest to contribute to a collaborative research effort. In addition, several workshops were held where you could learn the tricks of making CCD cameras and software produce the quality data that is the core of most astronomy research projects. Of particular interest to me was the use of the Peranso software to analyze light curves to reveal periodicity. Ten or even five years ago it would have been unthinkable that amateur astronomers would have the capability to produce data of the type that could detect earth-size planets in distant star systems automatically, collect data on variable stars, help determine the size and shape of near-earth asteroids, and study the afterglow from gamma ray bursts.
Now, with the introduction of low cost CCD cameras, software, and computers this is exactly what has happened. See, for example, the article in the September issue of Sky and Telescope that describes the discovery of XO-1b, a planet that orbits a G1 star 650 light years away from the Sun. The discovery of XO- 1b was made by amateurs Ron Bessinger, Bruce Gary, Paul Howell, and Tonny Vanmunster, who wrote the Peranso software that was used to analyze the periodic light data. I had the privilege of working with Ron Bessinger during our Bryce Canyon volunteer gig this past September. He is not only a skilled scientist, but is also skilled in all aspects of public outreach. Amateurs are making significant contributions to a scientific understanding of the cosmos. One example is UNC-Chapel Hill’s Gamma-Ray Burst Follow-Up Program, administered by Dr. Daniel E. Reichart.
Gamma ray bursts, detected by NASA’s SWIFT spacecraft, signal the death of massive stars and the birth of black holes. However, the afterglows are brief, requiring a quick and accurate observation response by earth-based telescopes. Clearly this is an area where small telescopes are better suited to the task. A group headed by Dr. Reichart has developed robotic telescope systems that are within the capability of many amateurs to build and administer. The Skynet Robotic Telescope Network now spans both North and South America and is growing rapidly. Terminator software is a key element in the Skynet that allows use of common offthe- shelf applications and equipment such as The Sky, MaximDL, and ASCOM cameras. Any amateur who has this equipment (and many do) can now join Skynet and gather research data from GRB afterglows. You can just script your telescope to go into action when the alert is beamed down from SWIFT, then go to sleep. If everything works you will wake up in the morning with a great data set.
Another area where amateur astronomers are making significant contributions is in the collection of light curve data from variable stars and near-earth asteroids (NEA). Cataclysmic Variables (CVs) are binary star systems that show periodicity in their magnitudes. The Center for Backyard Astrophysics (I think the name is a little degrading), directed by Dr. Joe Paterson from Columbia University, is composed of amateur astronomers located worldwide who form a data collection network. Target stars are identified in email notices from Dr. Paterson. Amateurs using their private telescopes and CCD cameras collect light curve data and send this data to Columbia University to analyze. Peranso (developed by Danish amateur Tony Vanmunster) is one piece of software used to analyze astronomical data sets and is capable of “splicing” multiple data sets to get light curves longer than that possible with observations from one single observatory location. The workshop I attended was designed to develop the skills necessary to analyze data sets for periodicity. The collection of data goes something like this. Find the target star (not always easy) and confirm its identity, take 100-200 CCD images of the star over a 5-6 hour period, and wake up in the morning and analyze the light data collected from the star. If you and your friends from other locations around the world see changes in the light magnitude you submit the data to Columbia for additional analysis.
When scientific papers are published the amateurs are listed as coauthors. Sounds simple, but your equipment and the weather have to cooperate. I joined this group in May, but have yet to submit any useful data sets. I’m still working on weather and automation issues. But I will soon join the network and begin collecting data sets while I sleep. What fun!
Other pro/am groups are collecting light data from NEAs. This data can be used to determine the shape and rotation rates of asteroids. The shape and rotation rates are fed into large computer modeling programs to predict orbit changes that could the move the path of the asteroid nearer earth. Good information to have!
Figure 1. The geometery of a gravitational microlensing event. The gravitational field of the lens both magnifies the image of the source star and brightens it. The presence of an exoplanet causes caustics in the lens. From the Proceedings for the 25th Annual Conference of the Society for Astronomical Sciences, page 98.
I mentioned the discovery of XO-1b above. The planets that are being discovered in other star systems are very large, similar in size to Jupiter. However, there are techniques being developed that will allow smaller earth size planets to be detected using small telescope systems. A group of amateurs and professional astronomers from Auckland Observatory in New Zealand is collecting light data changes in gravitational microlensing that occur around some star planet systems (see Figure 1). Dr. Grant Christie, director of the program in Auckland, reported on the details of the research and described how his group was collecting light data. As one might imagine, target stars that exhibit microlensing are very rare but as a group represent large numbers of potential targets for study. Target stars, about 600 per year, are reported by two surveys, one named the Optical Gravitational Lensing Experiment and the other the Microlensing Observations in Astrophysics based at Mt. John in New Zealand. A key element in this research is the MicroFun collaboration, headed by Professor Andrew Gould who is responsible for selecting target lists and coordinating the observing network. The microlensing alerts happen very fast and telescope systems must be ready to swing to action within an hour to observe a planet that is causing caustic effects in the gravitational lens. This is exciting stuff, and just the ticket for small telescope systems administered by amateur astronomers in private observatories.
Although I have given just a few examples of the current research pro/am collaborations, there are many more. I hope I have convinced you that the hobby of amateur astronomy has reached a level in sophistication where significant contributions to real science are becoming routine. Equipment and techniques will only improve in the future and the role of amateur astronomers in research will continue to grow.
References:
Proceedings of the 25th Annual Conference of the Society for Astronomical Sciences. May 23-25, 2006.