MY RESEARCH (Click to select descriptive pages)
I am an observational astronomer with interests in stellar evolution.  My students and I work primarily with photometry and spectroscopy in the optical region of the spectrum.  You can link to some of the places I work at below---notably the Gettysburg College Observatory and the National Undergraduate Research Observatory (NURO)----and there are links to PDF versions of selected papers at the end of this page Areas of Research Include: Photometric Searches for Transiting Exoplanets Transit Time Variations of Exoplanets High precision measurements of eclipsing/spectroscopic binary systems. Properties of open clusters. Rotation and activity in young stars. Light curves of supernovas. Asteroid astrometry and photometry. I have also published papers on Radial velocity curves of cepheids. Shadow bands at solar eclipses. Nuclear abundances in interstellar clouds using high resolution spectroscopy (my Ph.D. thesis). Physics and astronomy education. (see also Project CLEA pages)
Observatories
Gettysburg College Observatory Our main research instrument is a 16 inch (0.4m) f/11 Cassegrain equipped with a back-illuminated 1k square CCD camera (SiTE 003B chip, Roper Scientific camera), thermoelectrically cooled.
National Undergraduate Research Observatory (NURO) The telescope, owned by Lowell Observatory in Flagstaff, AZ, is a 32in (0.8 m) f/15 Cassegrain with a 2K back-illuminated CCD chip, LN cooled.
A Selection of Papers (PDF format) * indicates student co-author
Exoplanet Transits
· Neuhäuser, R., Errman, R., Berndt, A., Maciejewski, G, Takahashi, H, Chen, W.P., Dimitrov, D.P., Pribulla, T, Nikogossian, E.H., Jensen, E.L.N, Marschall, L., and 71 others, “Young Exoplanet Transit Initiative”, Astronomische Nachrichten, 332, 547-561 (2011)
Binary Stars
Morales, Juan Carlos, Torres, Guillermo, Marschall, Laurence A., and Brehm, William*, "Absolute Dimensions of the G7 + K7 Eclipsing Binary Star IM Virginis: Discrepancies With Stellar Evolution Models," Astrophys. Journal, 707, 671-685 (2009). Torres, Guillermo, Lacy, Claud H. Sandberg, Marschall, Laurence A.,  and Sheets, Holly A.*, “The Eclipsing Binary V1061 Cygni: Confronting Stellar Evolution Models for Active and Inactive Solar-Type Stars”, Astrophys.. Journal, 640, 1018-1038 (2006) Mader, Jeff A., Torres, Guillermo, Marschall, Laurence A.,  and Rizvi, Akbar H.*, “Optical Photometry and Spectroscopy of the ‘Cool Algol’ AV Delphinus: Determination of the Physical Properties”, Astron. Journal, 130, 234 (2005) Torres, Guillermo, Mader, Jeff A., Marschall, Laurence A., Neuhäuser, Ralph, and Duffy*, Alaine S., “Optical Photometry and X-Ray Monitoring of the “Cool Algol” BD+05˚706: Determination of the Physical Properties”, Astron. Journal, 125, 3237 (2003) Marschall, L.A., Stefanik, R.P., Lacy, C.H., Torres, G., Williams, D.B., and Agerer, F., "The Eclipsing Double-lined Spectroscopic Binary System V505 Persei", Astron. Journal, 114, 793 (1997) Marschall, L.A., and Mathieu, Robert D. "Parenago 1540: A Premain-Sequence Double-Lined Spectroscopic Binary Near the Orion Trapezium," Astron. Journal, 96, 1956 (1988)
Supernovas
Jha, S., Garnavich, P.M., Kirshner, R.P., Challis, P.M., Soderberg, A.M., Macri, L.M., Huchra, J. P., Barmby, P., Barton, E.J., Berlind, P., Brown, W., Caldwell, N., Calkins, M.L., Kannappan, S.J., Koranyi, D.M., Pahre, M.A., Rines, K.J., Stanek, K.Z., Stefanik, R.P., Szentgyorgi, A.H., Vaisanen, P., Wang, Z., Zajac, J, Riess, A.G., Filippenko, A.V., Li, W., Modjaz, M., Treffers, R.R., Hergenrother, C.W., Grebel, E.K., Seitzer, P., Jacoby, G.H., Benson, P.J., Rizvi, A.*, Marschall, L.A., Goldader, J., Beasley, M., Vacca, W.D., Leibundgut, B., Spyromilio, J., Schmidt, B., and Wood, P.R.,  "The Type-Ia Supernova 1998bu in M96 and the Hubble Constant", Astrophysical Journal Suppl., 125, 73-97 (1999) Richmond, M.R., Treffers, R.R., Filippenko, A.V., Van Dyk, S., Paik, Young, Marschall, L.A., Laaksonen, B.D.*, Macintosh, B., and McLean, I.S., "UBVRI Photometry of SN1994D in NGC 4526", Astron. Journal, 109, 2121 (1995)
Open Clusters
Montgomery, K.A, Marschall, L.A., and Janes, K.A., "CCD Photometry of the Old Open Cluster, M67", Astron. J., 106, 181 (1993). Marschall, L.A.,  and  Van  Altena,  William F. "Membership in the Young Cluster Trumpler 37", Astron. Journal, 94, 71 (1987).
Asteroids
Ratcliff, Stephen J., Balonek, Thomas J., Marschall, Laurence A., DuPuy, David L., Pennypacker, Carlton R, Verma, Ritu*, Alexov, Anastasia*, and Bonney, Vivian*, "The Measurement of Astronomical Parallaxes with CCD Imaging Cameras on Small Telescopes", American Journal of Physics, 61, 208 (1993).
Miscellaneous: Cepheids, Interstellar Lines, etc.
Marschall, L.A., Seeds, M.A., and Davis, R.J., "Radial Velocity and Light Variations of IR Cephei", Astron. Journal, 106, 1123 (1993) · Marschall, L.A., and Marschall, Emma B.*, "Reflections in a Polished Tube", The Physics Teacher, 21, 105 (1983). · Marschall, L.A., and Hobbs, L.M., "Interferometric Studies · of  Interstellar Calcium Lines", Astrophys. Journal, 177, 43-62 (1972).
Project CLEA and other Educational Articles
Marschall, Laurence A., Snyder, Glenn A., and Cooper, P.Richard, "A Desktop Universe for the Introductory Astronomy Laboratory", The Physics Teacher, 38, 536, (2000)