SDSS J102347.6+003841: A Millisecond Radio Pulsar Binary That Had A Hot Disk During 2000-2001 (2009)
Wang, Zhongxiang, Archibald, Anne M., Thorstensen, John R., Kaspi, Victoria M., Lorimer, Duncan R., Stairs, Ingrid, ...
The Sloan Digital Sky Survey (SDSS) source J102347.6+003841 was recently revealed to be a binary 1.69 millisecond radio pulsar with a 4.75 hr orbital period and a ~0.2 M_sun companion. Here we...
New Neighbors: Parallaxes of 18 nearby stars selected from the LSPM-north catalog (2009)
Lepine, Sebastien, Thorstensen, John R., Shara, Michael M., Rich, R. Michael
We present astrometric parallaxes for 18 suspected nearby stars selected from the LSPM-north proper motion catalog. Sixteen objects are confirmed to be main sequence M dwarfs within 16 parsecs of the...
SDSS J102347.6+003841: a millisecond radio pulsar binary that had a hot disk during 2000-2001 (2009)
Wang, Zhongxiang, Archibald, Anne M., Thorstensen, John R., Kaspi, Victoria M., Lorimer, Duncan R., Stairs, Ingrid, ...
The Sloan Digital Sky Survey (SDSS) source J102347.6+003841 was recently revealed to be a binary 1.69 ms radio pulsar with a 4.75 hr orbital period and a ∼0.2 M companion. Here, we analyze the...
Direct Distance Measurement to the Dusty White Dwarf GD 362 (2008)
Kilic, Mukremin, Thorstensen, John R., Koester, Detlev
We present trigonometric parallax observations of GD 362 obtained over seven epochs using the MDM 2.4m Hiltner Telescope. The existence of a dust disk around this possibly massive white dwarf makes...
The Rapidly Flaring Afterglow of the Very Bright and Energetic GRB 070125 (2008)
Updike, Adria C., Haislip, Joshua B., Nysewander, Melissa C., Fruchter, Andrew S., Kann, D. Alexander, Klose, Sylvio, ...
We report on multi-wavelength observations, ranging from the X-ray to radio wave bands, of the IPN-localized gamma-ray burst GRB 070125. Spectroscopic observations reveal the presence of absorption...
A New, Bright, Short-Period, Emission Line Binary in Ophiuchus (2008)
Stark, M. A., Wade, Richard A., Thorstensen, John R., Peters, Christopher S., Smith, Horace A., Miller, Robert D., ...
The 11th magnitude star LS IV -08 3 has been classified previously as an OB star in the Luminous Stars survey, or alternatively as a hot subdwarf. It is actually a binary star. We present...
Photometry and astrometry of SS Leo Minoris during the 2006 October superoutburst (2007)
Shears, Jeremy, Boyd, David, Krajci, Tom, Koff, Robert, Thorstensen, John R., Poyner, Gary
We report unfiltered CCD observations of the first confirmed superoutburst of the SU UMa-type dwarf nova SS LMi in October 2006. From a quiescent magnitude of around 21.7 it rose to 16.2, an outburst...
The Unusual Cataclysmic Binary Star RBS 0490 and the Space Density of Cataclysmics (2006)
Thorstensen, John R., Lepine, Sebastien, Shara, Michael
RBS (Rosat Bright Source) 0490 is a cataclysmic variable star (CV) with unusually strong emission lines. The strength of the emission lines led to a suggestion that the object is intrinsically faint...
Orbital Period of the Dwarf Nova RXS J053234.9+624755 (2006)
Kapusta, Ann B., Thorstensen, John R.
We report spectroscopy of the newly discovered SU Ursae Majoris dwarf nova identified with the x-ray source RXS J053234.9+624755. Radial velocities of the H-alpha emission line in the quiescent state...
Spectroscopy of Four Cataclysmic Variables with Periods above 7 Hours (2005)
Peters, Christopher S., Thorstensen, John R.
We present spectroscopy of four cataclysmic variables. Using radial velocity measurements, we find orbital periods for the first time. The stars and their periods are GY Hya, 0.347230(9) d; SDSS...
A Spectroscopic Study of HL Canis Majoris (2005)
Sheets, H. A., Thorstensen, John R.
We present optical spectroscopy of the dwarf nova HL Canis Majoris over a span of four years. The observations were made during standstill, outburst, and quiescence. We determine an orbital period of...
Spectroscopy of Seven Cataclysmic Variables with Periods Above Five Hours (2004)
Thorstensen, John R., Fenton, William H., Taylor, Cynthia J.
We present spectroscopy of seven cataclysmic variable stars with orbital periods P(orb) greater than 5 hours, all but one of which are known to be dwarf novae. Using radial velocity measurements we...
Thorstensen, John R., Fenton, William H., Patterson, Joseph O., Kemp, Jonathan, Krajci, Thomas, Baraffe, Isabelle
We present spectroscopy and time-series photometry of the newly discovered dwarf nova 1RXS J232953.9+062814. Photometry in superoutburst reveals a superhump with a period of 66.06(6) minutes. The low...
The Long-Period Orbit of the Dwarf Nova V630 Cassiopaeia (2001)
Orosz, Jerome A., Thorstensen, John R., Honeycutt, R. Kent
We present extensive spectroscopy and photometry of the dwarf nova V630 Cassiopeiae. A late-type (K4-5) absorption spectrum is easily detectable, from which we derive the orbital parameters. We find...
The Expansion Center and Dynamical Age of the Galactic Supernova Remnant Cassiopeia A (2001)
Thorstensen, John R., Fesen, Robert A., Bergh, Sidney Van Den
We present proper motions for 21 bright main shell and 17 faint, higher-velocity, outer ejecta knots in the Cas A supernova remnant and use them to derive new estimates for the remnant's expansion...
Spectroscopy and Component Masses of the Eclipsing Dwarf Nova HS0907+1902 (2000)
HS0907+1902 was recently discovered to be one of a handful of deeply eclipsing dwarf novae with periods longward of the 2 -- 3 hr `gap'. This paper presents orbit-resolved spectra and time series...
The Post-Common Envelope and Pre-Cataclysmic Binary PG 1224+309 (1998)
Orosz, Jerome A., Wade, Richard A., Harlow, Jason J. B., Thorstensen, John R., Taylor, Cynthia J., Eracleous, Michael
We have made extensive spectroscopic and photometric observations of PG 1224+309, a close binary containing a DA white dwarf primary and an M4+ secondary. The H alpha line is in emission due to...
The Century Survey: A Deeper Slice of the Universe (1997)
Geller, Margaret J., Kurtz, Michael J., Thorstensen, John R., ...
The ``Century Survey'' (CS hereafter) is a complete redshift survey of a 1$^\circ$-wide strip. It covers 0.03 steradians to a limiting m$_R$ = 16.13. The survey is 98.4% complete and contains 1762...