Mississauga Astronomical Society

            Twentyninth Meeting

             Speaker’s Night

Day:                Friday, Oct. 29, 2004

Speakers:   Dave Lane  - guest speaker

                    John Boyd

Building, Automating and using a Backyard Observatory for Research

Dave Lane, a professional electronic designer, is currently the second vice president of the Royal Astronomical Society of Canada, a member of the Halifax Centre, author of the software program “Earth Centered Universe”, and the systems administrator for the Astronomy and Physics Department of St. Mary’s University in Halifax.  He has built the Abbey Ridge Observatory which is engaged in a supernova searching.

Dave stated that an amateur can contribute to useful astronomical science. There are three types of work possible:

i) new discoveries such as variable stars, asteroids, comets, novae, and supernovae. There is much excitement in finding something no one has ever seen before, but the disadvantage is that there is a lot of competition to discover these things.

ii) time sensitive  observations such as determining the brightness of supernovae, position measurements of asteroids, occultation timings. These are valuable observations because professionals often cannot do these. Unfortunately the weather may not co-operate and work schedules may not allow the time.

iii) routine observations which contribute to the body of knowledge of astronomy such as variable star observations, asteroid positions, light curves of asteroids. Such observations may be valuable to scientists; on the other hand, the observations might never be used.

The Abbey Ridge Observatory Project

Dave was motivated to build this automated observatory by his interest in electronics. He decided to go ahead with the project in 2002, and he researched the telescope, mount, CCD camera, dome etc. Design goals included suitability for research projects, dark location, remote control from home office, “smart” enough to take images automatically and feasibility within the allotted budget.  The observatory is located 15 km west of Halifax, and has a limiting sky magnitude of 5.8. The 10 foot dome protects against wind and light trespass. The C11 scope is on a losmandy equatorial mount with a SBIG ST9 CCD camera. The pixels are 1.5 arcsec and image a 12.9 x 12.9 arc min field.

Development of the Remote Control and Automation Hardware and Software was motivated by the supernova search program. The observatory and dome rotation were semi-automated so that images could be taken either automatically or by remote control. Dave wrote a program in an easy-to-use language to interface with the telescope, focuser, dome and with the CCD camera. There currently 76 commands and more are pending. The dome itself has a bar code reader with codes every 5 degrees allowing the dome to follow the telescope.

Supernova Search Project

When a star explodes as a supernova (SN), its brightness increases by a billion and it rises to visibility in less than a day. An event can be expected on average once every 50 to 100 years in a galaxy. As a consequence, if thousands of galaxies are monitored, many

can be seen in a year. 328 extragalactic SN’s were discovered by amateurs in 2003 compared to 58 in 1995 and 16 in 1970. To discover these, one compares galaxy images to reference images and looks for a new “star”.  Type one supernovae, wherein a white dwarf in a binary system explodes after mass loading from a companion star, are the most useful for professional astronomers attempting to determine the expansion rate of the universe.

Paul Gray of the Moncton Centre developed the program, and Dave lane does the imaging from the Abbey Ridge Observatory. They take advantage of their northern latitude and scan the sky north of  55 degrees in the north west in the evening and north east in the morning – areas of the sky not easily visible from their competitors in Arizona and California. A search list of 2672 galaxies in 2033 fields and brighter than mag. 15.5, mainly spirals is examined and images are checked as soon as possible. About 300 galaxies per night can be imaged. The program stared in autumn of 2003. 7 supernovae have been seen in 7202 galaxies, none of them new discoveries, although two were “near misses”. 

Phil Mozel thanked Dave for a very interesting presentation.

Lunar Eclipse Oct. 27, 2004

John Boyd showed images of the total eclipse of the moon taken with a Nikon Digital camera and 500mm lens under perfect conditions in Ottawa. Almost nobody else in the audience saw the eclipse which was clouded out in the GTA.

 Submitted by Chris Malicki, Secretary  Chris Malicki, Secretary                               back to M.A.S. meeting reports page
Mississauga Astronomical Society