Results 31 to 40 of about 24,589 (267)

Hubble Space Telescope Fine Guidance Sensor Parallaxes For Four Classical Novae [PDF]

, 2013
We have used data obtained with the Fine Guidance Sensors on the Hubble Space Telescope to derive precise astrometric parallaxes for four classical novae: V603 Aql, DQ Her, GK Per, and RR Pic.
Benedict, G. Fritz, Bornak, Jilian, Harrison, Thomas E., McArthur, Barbara E.   +3 more
core   +1 more source

Polarization observations of DQ Her stars and other cataclysmic variables [PDF]

Monthly Notices of the Royal Astronomical Society, 1986
© Royal Astronomical Society. Linear and circular polarizations are presented for the DQ Her stars FO Aqr, AE Aqr, EX Hya, AO Psc and V1223 Sgr and for 17 other cataclysmic variables. Upper limits (~0.1 per cent in circular) are set to any periodic varia- tions in the polarization for the DQ Her stars.
openaire   +1 more source

Missing metals in DQ stars: a compelling clue to their origin

Monthly Notices of the Royal Astronomical Society
ABSTRACT White dwarf stars frequently experience external pollution by heavy elements, and yet the intrinsically carbon-enriched DQ spectral class members fail to exhibit this phenomenon, representing a decades-old conundrum. This study reports a high-resolution spectroscopic search for Ca ii in classical DQ white dwarfs, finding that ...
J Farihi, P Dufour, T G Wilson
openaire   +2 more sources

Double White Dwarf Binaries in SDSS-V DR19: The Discovery of a Rare DA+DQ White Dwarf Binary with a 31 hr Orbital Period

The Astrophysical Journal
Binaries of two white dwarfs (WDs) are an important class of astrophysical objects that help us reconstruct the complex processes involved in stellar evolution and are theorized to lead to Type Ia supernovae.
Gautham Adamane Pallathadka, Vedant Chandra, Boris T. Gänsicke, Nadia L. Zakamska, Detlev Koester, Yossef Zenati, Nicole R. Crumpler, Stefan M. Arseneau, J. J. Hermes, Matthias R. Schreiber, Keivan G. Stassun, Axel Schwope, Kareem El-Badry, Gagik Tovmassian, Tim Cunningham, Sean Morrison   +15 more
doaj   +1 more source

Photometric and Spectroscopic Analysis of Cool White Dwarfs with Trigonometric Parallax Measurements [PDF]

, 2000
A photometric and spectroscopic analysis of 152 cool white dwarf stars is presented. The discovery of 7 new DA white dwarfs, 2 new DQ white dwarfs, 1 new magnetic white dwarf, and 3 weak magnetic white dwarf candidates, is reported, as well as 19 known ...
Borysow A., Harrington R. S., Jorgensen U. G., Koester D., Liebert J., Maria Teresa Ruiz, P. Bergeron, S. K. Leggett, Strand K. Aa., Wehrse R.   +9 more
core   +2 more sources

Revealing the Hidden Role of Cd in p‐Type Mg3Sb2: Enhanced Thermoelectric Performance by Grain Boundary Segregation Engineering

Advanced Functional Materials, EarlyView.
The hidden role of Cd segregation at grain boundaries is revealed in p‐type Mg3Sb2 by atom probe tomography and other advanced characterizations. Grain boundary Cd enrichment suppresses the SbMg+ hole‐killer formation and lowers potential barriers, enhancing electrical conductivity.
Zhou Li, Deming Dong, Xiaoyu Yang, Jun Qian, Mengruizhe Kong, Han Wan, Ni Ma, Wei Bai, Pengfei Nan, Binghui Ge, Jiming Song, G. Jeffrey Snyder, Yuan Yu   +12 more
wiley   +1 more source

A New Window for Studying Intermediate Polars and Tilted Accretion Disk Precession

The Astrophysical Journal
TV Col is a long-period eclipsing intermediate polar (IP) prototype star for the negative superhump (NSH) system. We investigate the eclipse minima, eclipse depth, and NSH amplitude based on TESS photometry.
Qi-Bin Sun, Sheng-Bang Qian, Li-Ying Zhu, Wen-Ping Liao, Er-Gang Zhao, Fu-Xing Li, Xiang-Dong Shi, Min-Yu Li   +7 more
doaj   +1 more source

How the Carrier Mobility and Seebeck Coefficient of Doped Semiconducting Polymers Are Controlled by Counterion Interactions and Mesoscale Order

Advanced Functional Materials, EarlyView.
Conventional doping of P3HT with F4TCNQ results in poor charge transport. However, when F4TCNQ is exchanged with LiTFSI, the transport characteristics are greatly enhanced. We find the increase in charge transport is directly related to an increase in the mesoscale ordering of P3HT, resulting in longer and better‐connected transport pathways.
Quynh M. Duong, Diego Garcia Vidales, Xinyu Liu, Charlene Z. Salamat, Austin Ready, Hashim Al Khunaizi, Mei Matsumoto, Alexander M. Spokoyny, Sarah H. Tolbert, Benjamin J. Schwartz   +9 more
wiley   +1 more source

An All-sky Survey of White Dwarf Merger Remnants: Far-Ultraviolet Is the Key

The Astrophysical Journal
The majority of merging white dwarfs leave behind a white dwarf remnant. Hot/warm DQ white dwarfs with carbon-rich atmospheres have high masses and unusual kinematics. All evidence points to a merger origin.
Mukremin Kilic, Pierre Bergeron, Warren R. Brown, Simon Blouin, Gracyn Jewett, Adam Moss, Patrick Dufour, Olivier Vincent   +7 more
doaj   +1 more source

Taking Advantage of the COS Time-Tag Capability: Observations of Pulsating Hot DQ White Dwarfs and Discovery of a New One

, 2011
We present an analysis of the ultraviolet light curves of five Hot DQ white dwarfs recently observed with the Cosmic Origins Spectrograph (COS) on board the Hubble Space Telescope (HST).
Bergeron, P., Béland, S., Chayer, P., Dufour, P., Fontaine, G.   +4 more
core   +1 more source