Doctoral Dissertations


"To understand our own solar origins, we must investigate the composition of the protoplanetary disk from which the solar system formed. To infer this, we study analogs to the early solar system called T Tauri stars. These objects are low-mass, pre-main sequence stars surrounded by circumstellar disks of material from which planets are believed to form. We present high-resolution, near-infrared spectroscopic data for the T Tauri stars DR Tau and AA Tau using NIRSPEC at the Keck II telescope. For DR Tau, a spectro-astrometric analysis was performed, obtaining sub-seeing spatial information on water emission. Alongside a disk model, we constrained the viewing geometry of the disk (position angle ~140⁰, inclination ~13⁰) and the emitting region of the water emission lines (~0.056 - 0.38 AU). For AA Tau, we observed a superposition of strong water and OH absorption and emission features from two separate years, 2010 and 2014. During that time frame, AA Tau went through a dimming event, the effects of which we analyzed and used to discuss the implications for the source of the dimming event."--Abstract, page iii.


Gibb, Erika

Committee Member(s)

Wilking, Bruce
Parris, Paul Ernest, 1954-
Yamilov, Alexey
Brittain, Sean



Degree Name

Ph. D. in Physics


National Science Foundation (U.S.)


Support from the NASA-Missouri Space Grant Consortium, the University of Missouri St. Louis’s College of Arts & Sciences for a dissertation writing fellowship, NSF’s Stellar Astronomy program, and the American Recovery and Reinvestment Act of 2009 (NSF 0908230), JPL (RSA No: 1423736), and the NASA Exobiology and Evolutionary Biology program (NNX07AK38G)


Missouri University of Science and Technology

Publication Date

Fall 2016


viii, 76 pages

Note about bibliography

Includes bibliographic references (pages 69-75).


© 2016 Logan Ryan Brown, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Subject Headings

T Tauri stars
Protoplanetary disks
Stars -- Formation

Thesis Number

T 11015

Electronic OCLC #