The South Dome

The South Dome is a Technical Innovators 10-foot HomeDome that was purchased from a local amateur astronomer in 2010. For those of you from Baltimore, the person I bought the dome from was Norm Lewis, chief meteorologist at Channel 2, WMAR-TV. When Norm decided to retire and return to his native Florida he elected not to take the observatory with him and so offered it up on AstroMart for a very good price. In fact, the dome started life as a “ProDome” model, but none of the motorized controls were included in the sale as they had been fried by a lightning strike. The dome sits on an octagonal platform built like a standard outdoor deck. Similar to the North Dome, no attempt was made to seal the dome against the elements. No rain or snow gets into the dome but cool air can flow from under the building and vents through the track and wheel assemblies. This helps to keep the inside cool during the summer.

Here is the octagonal deck ready to receive the 10-foot dome. Note the central hole, through which I built a 12-inc diameter concrete pillar to anchor the mounting.

Equipment

The telescope in the South Dome is a 16-inch f/10 Meade LX200 ecm Schmidt-Cassegrain.  The primary science instrument for this telescope is a Shelyak Instruments LHiRes III spectrograph.  A variety of spectral resolving powers are available via 2400, 1200, 600, 300, and 150 line/mm gratings and slits ranging from 19  to 100 microns.  Using the 2400-line grating and 19-micron slit results in a resolving power of around 15000 – or a bit better that 0.4 Angstroms at 5000 Angstroms.   Given the telescope’s focal length of around 3950mm and the typically 2.5 arcsecond seeing I seldom (if ever) use the 19-micron slit, opting instead to use either the 23-micron or 35-micron slits, thus sacrificing resolving power to increase throughput.  The main science data camera is a Santa Barbara Instrument Group (SBIG) ST8xme camera with class 1 chip.  The guide camera is an SBIG remote guide head connected through an expansion port on the ST8.

Science Projects

The #1 16-inch, a Meade 16-inch f/10 LX200 ECM on an Astro-Physics 1200GTO mount, shown here with LHiRes Spectrograph.

Data from the South Dome has supported several projects in the past year, including a study of three Wolf-Rayet stars in Cygnus, monitoring Hydrogen and Helium absorption lines in the atmosphere of delta Orionis (Mintaka) and contributing to a world-wide spectral database of Nova Delphini 2013 observations.  The primary targets for the #1 16-inch & spectrograph are young massive stars with vigorous “stellar winds”, such as giant O and B stars, and Wolf-Rayet stars, many of which comprise the most massive stars in the galaxy, typically doomed to end their lives in spectacular explosions known as supernovae.