The Discovery of Binary White Dwarfs that will Merge within 500 Myr (2009)
Kilic, Mukremin, Brown, Warren R., Prieto, Carlos Allende, Kenyon, S. J.
We present radial velocity observations of four extremely low-mass (0.2 Msol) white dwarfs. All four stars show peak-to-peak radial velocity variations of 540 - 710 km/s with 1.0 - 5.9 hr periods....
A Spitzer Search for Substellar Companions to Low Mass White Dwarfs (2009)
Kilic, Mukremin, Brown, Warren R., McLeod, B.
The formation scenarios for single low-mass (M < 0.45 Msol) white dwarfs include enhanced mass loss from a metal-rich progenitor star or a common envelope phase of a solar-like star with a close-in...
Kilic, Mukremin, Gould, Andrew, Koester, Detlev
We present Spitzer IRAC photometry of white dwarf remnants of 14 stars with M = 3-5 Msol. We do not detect mid-infrared excess around any of our targets. By demanding a 3 sigma photometric excess at...
No Neutron Star Companion To The Lowest Mass SDSS White Dwarf (2009)
Agueros, Marcel, Heinke, Craig, Camilo, Fernando, Kilic, Mukremin, Anderson, Scott, Freire, Paulo, ...
SDSS J091709.55+463821.8 (hereafter J0917+4638) is the lowest surface gravity white dwarf (WD) currently known, with log g = 5.55 +/- 0.05 (M ~ 0.17 M_sun; Kilic et al. 2007a,b). Such low-mass white...
Spitzer Observations of the Oldest White Dwarfs in the Solar Neighborhood (2009)
Kilic, Mukremin, Kowalski, Piotr M., Reach, William T., Von Hippel, Ted
We present Spitzer 5-15 μm spectroscopy of one cool white dwarf and 3.6-8 μm photometry of 51 cool white dwarfs with T_(eff) < 6000 K. The majority of our targets have accurate BVRIJHK photometry...
Spitzer Observations of the Oldest White Dwarfs in the Solar Neighborhood (2009)
Kilic, Mukremin, Kowalski, Piotr M., Reach, William T., Von Hippel, Ted
We present Spitzer 5-15 micron spectroscopy of one cool white dwarf and 3.6-8 micron photometry of 51 cool white dwarfs with T_eff < 6000 K. The majority of our targets have accurate BVRIJHK...
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 first mid-infrared spectra of cool white dwarfs (2008)
Kilic, Mukremin, Kowalski, Piotr M., Mullally, Fergal, Reach, William T., Von Hippel, Ted
We present the first mid-infrared spectra of two cool white dwarfs obtained with the Spitzer Space Telescope. We also present 3.5-8 µm photometry for 19 cool white dwarfs with 5000 K ≤ T-eff ≤...
Kilic, Mukremin, Farihi, J., Nitta, Atsuko, Leggett, S. K.
Here, we present near-infrared spectroscopic observations of 15 helium atmosphere, metal-rich white dwarfs obtained at the NASA Infrared Telescope Facility. While a connection has been demonstrated...
A Nearby Old Halo White Dwarf Candidate from the Sloan Digital Sky Survey (2008)
Hall, Patrick B., Kowalski, Piotr M., Harris, Hugh C., Awal, Akshay, Leggett, S. K., Kilic, Mukremin, ...
We report the discovery of a nearby, old, halo white dwarf candidate from the Sloan Digital Sky Survey. SDSS J110217.48+411315.4 has a proper motion of 1.75 arcsec/year and redder optical colors than...
The First Mid-Infrared Spectra of Cool White Dwarfs (2007)
Kilic, Mukremin, Kowalski, Piotr M., Mullally, Fergal, Reach, William T., Von Hippel, Ted
We present the first mid-infrared spectra of two cool white dwarfs obtained with the Spitzer Space Telescope. We also present 3.5-8 micron photometry for 19 cool white dwarfs with 5000K < Teff <...
Finding Planets Around White Dwarf Remnants of Massive Stars (2007)
Gould, Andrew, Kilic, Mukremin
Planet frequency shows a strong positive correlation with host mass from the hydrogen-burning limit to M ~ 2Msun. No search has yet been conducted for planets of higher-mass hosts because all...
The Future is Now: the Formation of Single Low Mass White Dwarfs in the Solar Neighborhood (2007)
Kilic, Mukremin, Stanek, K. Z., Pinsonneault, M. H.
Low mass helium-core white dwarfs (M < 0.45 Msun) can be produced from interacting binary systems, and traditionally all of them have been attributed to this channel. However, a low mass white dwarf...
The new class of dusty DAZ white dwarfs (2007)
Von Hippel, Ted, Kuchner, Marc J., Kilic, Mukremin, Mullally, Fergal, Reach, William T.
Our mid-infrared survey of 124 white dwarfs with the Spitzer Space Telescope and the IRAC imager has revealed an infrared excess associated with the white dwarf WD 2115-560 naturally explained by...
The Discovery of a Companion to the Lowest Mass White Dwarf (2007)
Kilic, Mukremin, Brown, Warren R., Prieto, Carlos Allende, Pinsonneault, M. H., Kenyon, S. J.
We report the detection of a radial velocity companion to SDSS J091709.55+463821.8, the lowest mass white dwarf currently known with M~0.17Msun. The radial velocity of the white dwarf shows...
The New Class of Dusty DAZ White Dwarfs (2007)
Von Hippel, Ted, Kuchner, Marc J., Kilic, Mukremin, Mullally, Fergal, Reach, William T.
Our mid-infrared survey of 124 white dwarfs with the Spitzer Space Telescope and the IRAC imager has revealed an infrared excess associated with the white dwarf WD 2115-560 naturally explained by...
Kilic, Mukremin, Redfield, Seth
We report the discovery of excess K-band radiation from a metal-rich DAV white dwarf star, WD1150-153. Our near infrared spectroscopic observations show that the excess radiation cannot be explained...
A Spitzer White Dwarf Infrared Survey (2006)
Mullally, F., Kilic, Mukremin, Reach, William T., Kuchner, Marc J., Von Hippel, Ted, Burrows, Adam, ...
We present mid-infrared photometry of 124 white dwarf stars with Spitzer Space Telescope. Objects were observed simultaneously at 4.5 and 8.0um with sensitivities better than 1 mJy. This data can be...
The Lowest Mass White Dwarf (2006)
Kilic, Mukremin, Prieto, Carlos Allende, Brown, Warren R., Koester, D.
Extremely low mass white dwarfs are very rare objects likely formed in compact binary systems. We present MMT optical spectroscopy of 42 low mass white dwarf candidates serendipitously discovered in...
Debris Disks Around White Dwarfs: The DAZ Connection (2006)
Kilic, Mukremin, Von Hippel, Ted, Leggett, S. K., Winget, D. E.
We present near-infrared spectroscopic observations of 20 previously known DAZ white dwarfs obtained at the NASA Infrared Telescope Facility. Two of these white dwarfs (G29-38 and GD362) are known to...
The Mystery Deepens: Spitzer Observations of Cool White Dwarfs (2006)
Kilic, Mukremin, Von Hippel, Ted, Mullally, Fergal, Reach, William T., Kuchner, Marc J., Winget, D. E., ...
We present 4.5$\mu$m and 8$\mu$m photometric observations of 18 cool white dwarfs obtained with the Spitzer Space Telescope. Our observations demonstrate that four white dwarfs with T_eff< 6000 K...
The Dust cloud around the White Dwarf G 29-38 (2005)
Reach, William T., Kuchner, Marc J., Von Hippel, Ted, Burrows, Adam, Mullally, Fergal, Kilic, Mukremin, ...
We present new observations of the white dwarf G 29-38 with the camera (4.5 and 8 microns), photometer (24 microns), and spectrograph (5.5-14 microns) of the Spitzer Space Telescope. This star has an...
The White Dwarf Luminosity Function from SDSS Imaging Data (2005)
Harris, Hugh C., Munn, Jeffrey A., Kilic, Mukremin, Liebert, James, Williams, Kurtis A., Von Hippel, Ted, ...
A sample of white dwarfs is selected from SDSS DR3 imaging data using their reduced proper motions, based on improved proper motions from SDSS plus USNO-B combined data. Numerous SDSS and followup...
Excess Infrared Radiation from a Massive DAZ White Dwarf: GD362 - a Debris Disk? (2005)
Kilic, Mukremin, Von Hippel, Ted, Leggett, S. K., Winget, D. E.
We report the discovery of excess K-band radiation from a massive DAZ white dwarf star, GD362. Combining infrared photometric and spectroscopic observations, we show that the excess radiation cannot...
Kilic, Mukremin, Mendez, R. A., Von Hippel, Ted, Winget, D. E.
We explore the nature of the faint blue objects in the Hubble Deep Field South. We have derived proper motions for the point sources in the Hubble Deep Field South using a 3 year baseline. Combining...
Measuring the evolution of the most stable optical clock G 117-B15A (2005)
Kepler, S. O., Costa, J. E. S., Castanheira, B. G., Winget, D. E., Mullally, Fergal, Nather, R. E., ...
We report our measurement of the rate of change of period with time dP/dt for the 215 s periodicity in the pulsating white dwarf G 117-B15A, the most stable optical clock known. After 31 years of...
Cool White Dwarfs in the Sloan Digital Sky Survey (2005)
Kilic, Mukremin, Munn, Jeffrey A., Harris, Hugh C., Liebert, James, Von Hippel, Ted, Williams, Kurtis A., ...
A reduced proper motion diagram utilizing Sloan Digital Sky Survey (SDSS) photometry and astrometry and USNO-B plate astrometry is used to separate cool white dwarf candidates from metal-weak,...
The White Dwarf Luminosity Function from Sloan Digital Sky Survey Imaging Data (1998)
Harris, Hugh C., Munn, Jeffrey A., Kilic, Mukremin, Liebert, James, Kleinman, S. J., Metcalfe, T. S., ...
A sample of white dwarfs is selected from the Sloan Digital Sky Survey (SDSS) Data Release 3 using their reduced proper motions, based on improved proper motions from combined SDSS and USNO-B data....