English
Related papers

Related papers: DA white dwarfs observed in LAMOST pilot survey

200 papers

We verified for photometric stability a set of DA white dwarfs with Hubble Space Telescope magnitudes from the near-ultraviolet to the near-infrared and ground-based spectroscopy by using time-spaced observations from the Las Cumbres…

We present a detailed model atmosphere analysis of hot white dwarfs in the Dark Energy Spectroscopic Instrument (DESI) Data Release 1. Our sample includes 19,321 unique targets with $G_{\rm BP}-G_{\rm RP}\leq0$. We use the DESI spectra…

A total of 81 DA white dwarfs have been observed with the Cosmic Origins Spectrograph on the Hubble Space Telescope in a snapshot program. The targets were selected to be in the $T_{\rm eff}$ range from 17000 - 25000 K, where optical metal…

Solar and Stellar Astrophysics · Physics 2012-09-27 Detlev Koester , Boris Gänsicke , Jonathan Girven , Jay Farihi

We perform a discrimination procedure with the spectral index diagram of TiO5 and CaH2+CaH3 to separate M giants from M dwarfs. Using the M giant spectra identified from the LAMOST DR1 with high signal-to-noise ratio (SNR), we have…

Astrophysics of Galaxies · Physics 2015-06-01 Jing Zhong , Sebastien Lepine , Jing Li , Li Chen , Jinliang Hou , Ming Yang , Guangwei Li , Yong Zhang , Yonghui Hou

Based on the astrometry and photometry in Gaia DR3, we identified new nearby white dwarfs and validated those that had been missed from recent white dwarf catalogues despite being previously documented. To ensure the reliability of their…

Solar and Stellar Astrophysics · Physics 2024-01-04 Alex Golovin , Sabine Reffert , Akash Vani , Ulrich Bastian , Stefan Jordan , Andreas Just

An initial assessment is made of white dwarf and hot subdwarf stars observed in the Sloan Digital Sky Survey. In a small area of sky (190 square degrees), observed much like the full survey will be, 269 white dwarfs and 56 hot subdwarfs are…

Recent massive sky surveys in different bandwidths are providing new opportunities to modern astronomy. The Virtual Observatory (VO) represents the adequate framework to handle the huge amount of information available and filter out data…

Solar and Stellar Astrophysics · Physics 2016-03-01 Esther Pérez-Fernández , Ana Ulla , Enrique Solano , Raquel Oreiro , Carlos Rodrigo

We present a progress report on the kinematical analysis of the entire SPY (ESO SN Ia Progenitor surveY) sample of about one thousand white dwarfs and hot subdwarfs. In a previous study (Pauli et al. 2003, 2006) 398 DA white dwarfs have…

Astrophysics · Physics 2007-05-23 R. Richter , U. Heber , R. Napiwotzki

We present a detailed analysis of 108 helium-line (DB) white dwarfs based on model atmosphere fits to high signal-to-noise optical spectroscopy. We derive a mean mass of 0.67 Mo for our sample, with a dispersion of only 0.09 Mo. White…

AIMS: With our low-resolution spectroscopic observing program for selected blue proper motion stars, we tried to find new white dwarfs (WDs) in the solar neighbourhood. METHODS: We used the LSPM catalogue with a lower proper motion limit of…

Solar and Stellar Astrophysics · Physics 2018-11-07 R. -D. Scholz , H. Meusinger , A. Schwope , H. Jahreiß , I. Pelisoli

The latest Gaia data release provides low-resolution spectra for approximately 100 000 white dwarfs. Though useful for pre-classification, they lack the resolution required for accurate spectral type and parameter determination, motivating…

Solar and Stellar Astrophysics · Physics 2026-05-19 Enrique Miguel García Zamora , Santiago Torres Gil , Alberto Rebassa Mansergas , Aina Ferrer i Burjachs

For some years now, we have been gathering optical spectra of DA white dwarfs in an effort to study and define the empirical ZZ Ceti instability strip. However, we have recently expanded this survey to include all the DA white dwarfs in the…

Astrophysics · Physics 2009-07-22 A. Gianninas , P. Bergeron , M. T. Ruiz

We present optical spectra of 144 white dwarfs detected in the Montreal-Cambridge-Tololo (MCT) colorimetric survey, including 120 DA, 12 DB, 4 DO, 1 DQ, and 7 DC stars. We also perform a model atmosphere analysis of all objects in our…

Solar and Stellar Astrophysics · Physics 2021-10-20 P. Bergeron , F. Wesemael , G. Fontaine , R. Lamontagne , S. Demers , A. Bédard , M. -J. Gingras , S. Blouin , M. J. Irwin , S. O. Kepler

Hot subdwarf star is a particular type of star that is crucial for studying binary evolution and atmospheric diffusion processes. In recent years, identifying Hot subdwarfs by machine learning methods has become a hot topic, but there are…

Solar and Stellar Astrophysics · Physics 2022-01-25 Lei Tan , Ying Mei , Zhicun Liu , Yangping Luo , Hui Deng , Feng Wang , Linhua Deng , Chao Liu

With tens to hundreds of spectra of white dwarfs being taken each night from multi-object spectroscopic surveys, automated spectral classification is essential as part of efficient data processing. In this study, we design a neural network…

In this paper, we apply the feature-integration idea to fuse the abstract features extracted by Se-ResNet with experience features into hybrid features and input the hybrid features to the Support Vector Machine (SVM) to classify Hot…

Solar and Stellar Astrophysics · Physics 2022-12-21 Cheng Zhongding , Kong xiaoming , Wu Tianmin , Bu Yude , Lei Zhenxin , Zhang Yatao , Yi Zhenping , Liu Meng

We describe a new survey for cool white dwarfs that supplements Sloan Digital Sky Survey photometry with USNO proper motions and follow-up spectroscopy. To date we have discovered and spectroscopically confirmed 80 new moderate temperature…

Most known white dwarfs in multiple systems with main sequence stars have been discovered with M-type companions, because the white dwarf causes detectable UV excess and bluer colors than expected from a single M star. Surveys have shown…

With the launch of the {\em Wide-field Infrared Survey Explorer} ({\em WISE}), a new era of detecting planetary debris and brown dwarfs around white dwarfs (WDs) has begun with the {\em WISE} InfraRed Excesses around Degenerates (WIRED)…

Solar and Stellar Astrophysics · Physics 2015-05-30 J. H. Debes , D. W. Hoard , S. Wachter , D. T. Leisawitz , M. Cohen

We present preliminary results of the quasar survey in Large Sky Area Multi- Object Fiber Spectroscopic Telescope (LAMOST) first data release (DR1), which includes pilot survey and the first year regular survey. There are 3921 quasars…

‹ Prev 1 4 5 6 7 8 10 Next ›