Zobrazeno 1 - 10
of 202
pro vyhledávání: '"Von Hippel, T."'
Autor:
von Hippel, T., Farihi, J., Provencal, J. L., Kleinman, S. J., Pringle, J. E., Swan, A., Fontaine, G., Hermes, J. J., Sargent, J., Savery, Z., Cooper, W., Kim, V., Kozyreva, V., Krugov, M., Kusakin, A., Moss, A., Ogloza, W., Pakstiene, E., Serebryanskiy, A., Sonbas, E., Walter, B., Zejmo, M., Zola, S.
More than 36 years have passed since the discovery of the infrared excess from circumstellar dust orbiting the white dwarf G29-38, which at 17.5 pc it is the nearest and brightest of its class. The precise morphology of the orbiting dust remains only
Externí odkaz:
http://arxiv.org/abs/2401.02558
Autor:
Walters, N., Farihi, J., Marsh, T. R., Breedt, E., Cauley, P. W., von Hippel, T., Hermes, J. J.
This study presents observations of two possible substellar survivors of post-main sequence engulfment, currently orbiting white dwarf stars. Infrared and optical spectroscopy of GD 1400 reveal a 9.98 h orbital period, where the benchmark brown dwarf
Externí odkaz:
http://arxiv.org/abs/2207.07022
Autor:
Otani, T., Lynas-Gray, A. E., Kilkenny, D., Koen, C., von Hippel, T., Uzundag, M., Vuckovic, M., Pennock, C. M., Silvotti, R.
AQ Col (EC 05217-3914) is one of the first detected pulsating subdwarf B (sdB) stars and has been considered to be a single star. Photometric monitoring of AQ Col reveals a pulsation timing variation with a period of 486 days, interpreted as time-del
Externí odkaz:
http://arxiv.org/abs/2109.05394
Autor:
Farihi, J., van Lieshout, R., Cauley, P. W., Dennihy, E., Su, K. Y. L., Kenyon, S. J., Wilson, T. G., Toloza, O., Gänsicke, B. T., von Hippel, T., Redfield, S., Debes, J. H., Xu, S., Rogers, L., Bonsor, A., Swan, A., Pala, A. F., Reach, W. T.
The infrared dust emission from the white dwarf GD 56 is found to rise and fall by 20% peak-to-peak over 11.2 yr, and is consistent with ongoing dust production and depletion. It is hypothesized that the dust is produced via collisions associated wit
Externí odkaz:
http://arxiv.org/abs/1808.09967
Observational tests of stellar and Galactic chemical evolution call for the joint knowledge of a star's physical parameters, detailed element abundances, and precise age. For cool main-sequence (MS) stars the abundances of many elements can be measur
Externí odkaz:
http://arxiv.org/abs/1802.06663
The rapidly evolving dust and gas extinction observed towards WD 1145+017 has opened a real-time window onto the mechanisms for destruction-accretion of planetary bodies onto white dwarf stars, and has served to underline the importance of considerin
Externí odkaz:
http://arxiv.org/abs/1707.09474
Autor:
Wagner-Kaiser, R., Sarajedini, A., von Hippel, T., Stenning, D. C., van Dyk, D. A., Jeffery, E., Robinson, E., Stein, N., Anderson, J., Jefferys, W. H.
We use Hubble Space Telescope (HST) imaging from the ACS Treasury Survey to determine fits for single population isochrones of 69 Galactic globular clusters. Using robust Bayesian analysis techniques, we simultaneously determine ages, distances, abso
Externí odkaz:
http://arxiv.org/abs/1702.08856
Autor:
Wagner-Kaiser, R., Stenning, D. C., Sarajedini, A., von Hippel, T., van Dyk, D. A., Robinson, E., Stein, N., Jefferys, W. H.
We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of 30 Galactic Globular Clusters to characterize two distinct stellar populations. A sophisticated Bayesian technique is employed to simultaneously s
Externí odkaz:
http://arxiv.org/abs/1609.01527
Autor:
Stenning, D. C., Wagner-Kaiser, R., Robinson, E., van Dyk, D. A., von Hippel, T., Sarajedini, A., Stein, N.
We develop a Bayesian model for globular clusters composed of multiple stellar populations, extending earlier statistical models for open clusters composed of simple (single) stellar populations (vanDyk et al. 2009, Stein et al. 2013). Specifically,
Externí odkaz:
http://arxiv.org/abs/1604.06073
Autor:
Wagner-Kaiser, R., Stenning, D. C., Robinson, E., von Hippel, T., Sarajedini, A., van Dyk, D. A., Stein, N., Jefferys, W. H.
We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of Galactic Globular Clusters to find and characterize two stellar populations in NGC 5024 (M53), NGC 5272 (M3), and NGC 6352. For these three cluste
Externí odkaz:
http://arxiv.org/abs/1604.06074