Eclipsing Binaries
My first love for astronomy research is with eclipsing binaries. Most of the systems I have studied are short period WUma’s and RS CVn's. Complete light curves are easily obtainable over the course of one single night with these types of systems. However, their curves are not quite as easily solved since a large fraction of them have filled their Roche Lobes. There in lies the challenge; mass transfer, star spots, reflection effect and third light anomalies make solving them very rewarding.
Here are some of the binaries I have studied since the observatory opened.
- RT Andromedae
- KV Geminorum
- TU Bootis
- WY Cancri
- T LMi
RT Andromedae
With a period of 0.628 days, this is an interesting system to say the least. This one is an RS CVn with a lot of spot activity. The light curve is very dynamic from week to week with the shoulders increasing and decreasing in intensity with no apparent periodicity. One new approach I am working on is modeling spot migration by simply solving short time curves using ELC (Eclipsing Light Curve) found and comparing spot solutions from one night to the next. To my knowledge this has not been done with any great degree of success, since the magnetic activity of these stars seem to be intertwined to a confusing degree. Preliminarily, we have had some minor successes in showing this migratory behavior. Check out the animation I made using Binary Maker. This was the result of three independent solutions for star spots as seen from the same orientation. Notice how the spots on the secondary (the star on the left) migrate from the pole at the top towards the bottom.
KV Geminorum
Originally designated as a c-type RR Lyrae system, it is easy to see how it could have been mis-identified since the curves from RRc’s are symmetrical. Light curve data on this system has been sparse and not quite good enough for proper identification, but Kam-Ching Leung and Kevin Lee at Behlen Observatory had pegged it as a WUMa in 1997. In the spring semester of ’07 it was targeted as a lab project by our own 312 Astrophysics class and its identity as a WUMa eclipsing binary was independently confirmed. Interestingly enough, the GCVS still has it listed as a RR Lyrae.
Pulsating Variables
An obvious segway to pulsating variables was born out of the KV Gem data. I have recently embarked on a long term research project involving short period pulsating variables, in particular, c-type RR Lyraes. The GCVS has myriad gaps that need to be filled, and a lot of these short period stars are surprisingly understudied. Some stars listed don't have "any" data all (more on archival astronomy later). We are currently using PERANSO period analysis software for maximum timings and period calculations and we are very pleased with the results. Here are some of the RR's that I am currently studying:
- CQ Boo
- CU Boo
- IS Com
- SX UMa
My Favorite Places
As both the Observatory and the Machine Shop Supervisor, I am in a unique position that gives me the opportunity to visit observatories around the world not only for research but for instrumentation development. I have been involved in developing CCD cameras and wavefront sensors for adaptive optics systems since 1991 for Scimeasure Analytical Systems.
Click on the links below to get a guided tour of the places I have visited or to get more details on the instrumentation I have worked on.
Some of the places I have visited:
Some of the places I have instruments: