Research Interests

My research interests span a large range of topics. I've used large arrays of optical telescopes to measure the diameters of individual stars while also using large arrays of radio telescopes to measure the sizes of dark matter halos around merging galaxies. I am currently working on refining a technique for finding the distances to certain pulsating stars (Cepheid variables) by watching how their brightness and color change with time. In addition I am working with Deidre Hunter on star formation in dwarf galaxies. I am also interested in archeoastronomy, particularly sundials. In January of 2005 two sundials I helped design landed on Mars aboard the Spirit and Opportunity Mars Exploration Rovers.

Since 2006 I have been working with the National Park Service on astronomy education in the national parks. At the January 2009 American Astronomical Society I presented the following poster on that work. You can download that poster here.

Here is my cv in (postscipt format) or in (pdf, which looks crummy on the screen, but prints great).

Here is my refereed publication list.

19. Simpson, C., Hunter, D., Nordgren, T. E., 2005, ``DDO 43: A Prototypical Dwarf Irregular Galaxy?", AJ, in press

18. Marconi, M., Nordgren, T., Bono, G., Schnider, G., Caputo, F, 2005, ``Predicted and Empirical Radii of RR Lyrae Stars", ApJL, 623L, 133

17. Ohishi, N., Nordgren, T. E., & Hutter, D. J., 2004, ``Assymetric Surface Brightness Distribution of Altair Observed with the Navy Prototype Optical Interferometer", ApJ, 612, 463

16. Marengo, M., Karovska, M., Sasselov, D. D., Papaliolios, C., Armstrong, J. T., & Nordgren, T. E., 2003, ``Theoretical Limb-Darkening for Classical Cepheids. II. Corrections for the Geometric Baade-Wesselink Method", ApJ, 589, 968

15. Dyck, H. M. & Nordgren, T. E., 2002, ``The Effect of TiO Absorption on Optical and Infrared Angular Diameters of Cool Stars", AJ, 124, 541.

14. Nordgren, T. E., Lane, B. F., Hindsley, R. B., & Kervella, P., 2002, ``Calibration of the Barnes-Evans Relation Using Interferometric Observations of Cepheids", AJ, 123, 3380.

13. Lane, B. F., Creech-Eakman, M. J., & Nordgren, T. E., 2002, ``Long Baseline Interferometric Observation of Cepheids", ApJ, 573, 330.

12. Aufdenberg, J. P., Hauschildt, P. H., Baron, E., Nordgren, T. E., Howard, I. D., Burnlley, A., Gordon, K. D., & Stansberry, J. A., 2002 ``The Spectral Energy Distribution and Mass-Loss Rate of the A-Type Supergiant Deneb", ApJ, 570, 344.

11. Nordgren, T. E., Sudol, J. J., & Mozurkewich, D., 2001, ``Comparison of Stellar Angular Diameters from the NPOI, the Mark III Optical Interferometer, and the Infrared Flux Method", AJ, 122, 2707.

10. Hummel, C. A., Carquillat, J.-M., Genestet, N., Griffin, R. F., Boden, A. F., Hajian, A. R., Mozurkewich, D. & Nordgren, T. E., 2001, ``Orbital and Stellar Parameters of Omicron Leonis from Spectroscopy and Interferometry", AJ, 121, 1623.

9. Armstrong, J.T, Nordgren, T. E., Germain, M. E., Hajian, A. R., Hindsley, R. B., Hummel, C. A. & Thessin, R. N., 2001, ``Diameters of delta Cephei and eta Aquilae Measured with the Navy Prototype Optical Interferometer'', AJ, 121, 476.

8. Nordgren, T. E., Chengalur, J. N., Salpeter, E. E., & Terzian, Y., 2000, ``The 1.0 Mpc Galaxy Pair Sample'', ApJ, 544, 176.

7. Nordgren, T. E., Armstrong, J. T., Germain, M. E., Hindsley, R. B., Hajian, A. R., Sudol, J. J., & Hummel, C. A., 2000, ``Astrophysical Quantities of Cepheid Variables Measured with the NPOI'', ApJ, 543, 972.

6. Hummel, C. A., White, N. M., Elias~II, N. M., Hajian, A. R., & Nordgren, T. E., 2000, ``Zeta Orionis A is a Double Star", ApJL, 540, L91.

5. Nordgren, T. E., 1999, ``Stellar Angular Diameters of Late-Type Giants and Supergiants Measured with the Navy Prototype Optical Interferometer'', AJ, 118, 3032.

4. Nordgren, T. E., Chengalur, J. N., Salpeter, E. E., & Terzian, Y., 1998, ``Very Wide Galaxy Pairs of the Northern Sky'', ApJSupp, 115, 43.

3. Nordgren, T. E., Chengalur, J. N., Salpeter, E. E., & Terzian, Y., 1997, ``Close Galaxy Pairs in Regions of Low and Medium Galaxy Density: The Southern Sky'', AJ, 114, 913.

2. Nordgren, T. E., Chengalur, J. N., Salpeter, E. E., & Terzian, Y., 1996, ``Close Galaxy Pairs in Regions of Medium Galaxy Density: The Northern Sky'', AJ, 114, 77.

1. Nordgren, T. E., Cordes, J. M., & Terzian, Y., 1992, ``The Scale Height of the Galactic Free Electron Cloud'', AJ, 104, 1465.

Here :

Glacier Point Movie (animated gif 13 MB)

Chaco Canyon Movie (animated gif 7 MB)