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Caught speeding:Clocking the fastest-spinning brown dwarfs（图）
Caught speeding Clocking fastest-spinning brown dwarfs
2021/4/23
Astronomers have discovered the most rapidly rotating brown dwarfs -- three brown dwarfs that each complete a full rotation roughly once every hour. The rate is so extreme that if they rotated any fas...
OU Astrophysicist Predicts Detached Eclipsing White Dwarfs to Merge Into an Exotic Star（图）
OU Astrophysicist Predicts Detached Eclipsing White Dwarfs to Merge Exotic Star
2017/9/5
A University of Oklahoma astrophysicist, Mukremin Kilic, and his team have discovered two detached, eclipsing double white dwarf binaries with orbital periods of 40 and 46 minutes, respectively. White...
Brown dwarfs are smaller than stars, but more massive than giant planets. As such, they provide a natural link between astronomy and planetary science. However, they also show incredible variation whe...
Brown Dwarfs,Stars Share Formation Process,New Study Indicates
Brown Dwarfs Stars Share Formation Process
2015/8/4
Astronomers using the Karl G. Jansky Very Large Array (VLA) have discovered jets of material ejected by still-forming young brown dwarfs. The discovery is the first direct evidence that brown dwarfs, ...
Two New Tidally Distorted White Dwarfs
Galaxy stellar content Distorted White Dwarfs J174140.49+652638.7
2012/2/23
We identify two new tidally distorted white dwarfs (WDs), SDSS J174140.49+652638.7 and J211921.96-001825.8 (hereafter J1741 and J2119). Both stars are extremely low mass (ELM, < 0.2 Msun) WDs in short...
A Search for High Proper Motion T Dwarfs with Pan-STARRS1 + 2MASS + WISE
Search Proper Motion Dwarfs
2011/10/13
We have searched ~8200 sq. degs for high proper motion (~0.5-2.7"/year) T dwarfs by combining first-epoch data from the Pan-STARRS1 (PS1) 3-Pi Survey, the 2MASS All-Sky Point Source Catalog, and the W...
Identification of field dwarfs and giants in RAVE
surveys–catalogues–techniques: photometric
2011/10/13
The second RAdial Velocity Experiment (RAVE) Data Release (DR2) derives log g values but we present a simpler and cleaner method of identifying dwarfs and giants using only magnitudes, which does not ...
S. Chandrasekhar: White Dwarfs, $H^-$ ion,.., Black holes
Black holes Chandrasekhar White Dwarfs relativistic quantum
2011/8/5
Abstract: This is a concise review, addressed to undergraduate students, of S. Chandrasekhar's oeuvre in astrophysics, ranging from his early studies on white dwarfs using relativistic quantum statist...
Magnetic Fields in Earth-like Exoplanets and Implications for Habitability around M-dwarfs
magnetic fields exoplanets habitability
2011/10/9
We present estimations of dipolar magnetic moments for terrestrial exoplanets using the Olson & Christiansen (2006) scaling law and assuming their interior structure is similar to Earth. We find that ...
Near-infrared Linear Polarization of Ultracool Dwarfs
Near-infrared Linear Polarization tracool Dwarfs
2011/10/8
We report on near-infrared J- and H-band linear polarimetric photometry of eight ultracool dwarfs (two late-M, five L0-L7.5, and one T2.5) with known evidence for photometric variability due to dust c...
Nucleosynthesis during the Merger of White Dwarfs and the Origin of R Coronae Borealis Stars
Dwarfs Origin Borealis Stars
2011/10/8
Many hydrogen deficient stars are characterised by surface abundance patterns that are hard to reconcile with conventional stellar evolution. Instead, it has been suggested that they may represent the...
Transformations between WISE, 2MASS, SDSS and BVRI photometric systems: I. Transformation equations for dwarfs
cosmology – gravitational lensing – fl exion – dark matter halo
2011/9/29
We present colour transformations for the conversion of the W1 and W2 magnitudes of WISE photometric system to the Johnson-Cousins' BVRI, SDSS (gri), and 2MASS (JHK_s) photometric systems, for dwarfs....
The HARPS search for southern extrasolar planets. XXV. Four new planets in orbit around the moderatly active dwarfs HD 63765, HD 104067, HD 125595, and HIP 70849
Techniques: radial velocities – Methods: data analysis – genetic algorithm Stars: individual:HD 104067 HD 125595 HIP 70849
2011/9/27
We report the detection of four new extrasolar planets in orbit around the moderately active stars HD 63765, HD 104067, HIP 70849, and HD 125595 with the HARPS Echelle spectrograph mounted on the ESO ...
A number of so-called ultra-cool white dwarfs have been detected in different surveys so far. However, based on anecdotal evidence it is believed that most or all of these ultra-cool white dwarfs are ...
The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
chemical differentiation thermonuclear supernovae
2011/1/10
Gravitational settling of 22Ne in cooling white dwarfs can affect the outcome of thermonuclear supernovae. We investigate how the supernova energetics and nucleosynthesis are in turn influenced by thi...