The classification of intrinsic variable stars. II. The red variables of S and related types

1972 ◽  
Vol 177 ◽  
pp. 489 ◽  
Author(s):  
O. J. Eggen
Keyword(s):  
Variable Stars ◽  
Intrinsic Variable

scholarly journals Learn from every mistake! Hierarchical information combination in astronomy

2016 ◽  
Vol 12 (S325) ◽  
pp. 39-45 ◽  
Author(s):  
Maria Süveges ◽  
Sotiria Fotopoulou ◽  
Jean Coupon ◽  
Stéphane Paltani ◽  
Laurent Eyer ◽  
...  
Keyword(s):  
Big Data ◽  
Probability Distributions ◽  
Variable Stars ◽  
Alternative Methods ◽  
Photometric Redshift ◽  
Promising Tool ◽  
Combination Methods ◽  
General Improvement ◽  
Output Probability

AbstractThroughout the processing and analysis of survey data, a ubiquitous issue nowadays is that we are spoilt for choice when we need to select a methodology for some of its steps. The alternative methods usually fail and excel in different data regions, and have various advantages and drawbacks, so a combination that unites the strengths of all while suppressing the weaknesses is desirable. We propose to use a two-level hierarchy of learners. Its first level consists of training and applying the possible base methods on the first part of a known set. At the second level, we feed the output probability distributions from all base methods to a second learner trained on the remaining known objects. Using classification of variable stars and photometric redshift estimation as examples, we show that the hierarchical combination is capable of achieving general improvement over averaging-type combination methods, correcting systematics present in all base methods, is easy to train and apply, and thus, it is a promising tool in the astronomical “Big Data” era.

scholarly journals Summary-Introduction: Velocity Fields and Associated Thermodynamic Variations in the External Layers of Intrinsic Variable Stars

1960 ◽  
Vol 12 ◽  
pp. 131-193 ◽  
Author(s):  
P. Ledoux ◽  
C. A. Whitney
Keyword(s):  
Radial Velocity ◽  
Variable Stars ◽  
Velocity Fields ◽  
Light Spectrum ◽  
Physical Modification ◽  
Intrinsic Variable

By intrinsic variable stars, we mean those stars which present variations in light, spectrum and radial velocity which cannot be accounted for in terms of purely geometrical or orbital factors; so that we have to appeal to some kind of periodic physical modification of the star.

scholarly journals A search for variable subdwarf B stars in TESS full frame images – I. Variable objects in the southern ecliptic hemisphere

2020 ◽  
Vol 499 (4) ◽  
pp. 5508-5526
Author(s):  
S K Sahoo ◽  
A S Baran ◽  
S Sanjayan ◽  
J Ostrowski
Keyword(s):  
Preliminary Analysis ◽  
Variable Stars ◽  
Eclipsing Binaries ◽  
Spectral Classification ◽  
B Stars ◽  
Mode Identification ◽  
Pulsating Stars ◽  
Subdwarf B Stars ◽  
Amplitude Spectra

ABSTRACT We report the results of our search for pulsating subdwarf B stars in full frame images, sampled at 30 min cadence and collected during Year 1 of the TESS mission. Year 1 covers most of the southern ecliptic hemisphere. The sample of objects we checked for pulsations was selected from a subdwarf B stars data base available to public. Only two positive detections have been achieved, however, as a by-product of our search we found 1807 variable objects, most of them not classified, hence their specific variability class cannot be confirmed at this stage. Our preliminary discoveries include: 2 new subdwarf B (sdB) pulsators, 26 variables with known sdB spectra, 83 non-classified pulsating stars, 83 eclipsing binaries (detached and semidetached), a mix of 1535 pulsators and non-eclipsing binaries, two novae, and 77 variables with known (non-sdB) spectral classification. Among eclipsing binaries we identified two known HW Vir systems and four new candidates. The amplitude spectra of the two sdB pulsators are not rich in modes, but we derive estimates of the modal degree for one of them. In addition, we selected five sdBV candidates for mode identification among 83 pulsators and describe our results based on this preliminary analysis. Further progress will require spectral classification of the newly discovered variable stars, which hopefully include more subdwarf B stars.

scholarly journals Re-classification of ROTSE-I δ Scuti stars

2004 ◽  
Vol 193 ◽  
pp. 279-282
Author(s):  
H. Jin ◽  
S.-L. Kim ◽  
C.-U. Lee ◽  
D.-J. Lee ◽  
K.-S. Kim
Keyword(s):  
Decomposition Analysis ◽  
Variable Stars ◽  
Fourier Decomposition ◽  
Eclipsing Variable Stars ◽  
Scuti Stars ◽  
Δ Scuti Stars

AbstractWe present new multiband photometric results for ROTSE-I δ Sct stars and the Fourier decomposition analysis. Our result shows that most of the stars classified as ROTSE-I δ Sct stars seem to be W UMa type eclipsing variable stars.

scholarly journals Comparison of Mean Light Curve Parameters of M, S and C Mira and Semi-Regular Variable Stars Using 75 Years of AAVSO Data

2000 ◽  
Vol 177 ◽  
pp. 165-170
Author(s):  
Marie-Odile Mennessier ◽  
Hichame Boughaleb ◽  
Janet A. Mattei
Keyword(s):  
Light Curve ◽  
Variable Stars ◽  
Light Curves ◽  
Long Period ◽  
Regular Variable

Using 75 years of AAVSO data, mean light curve parameters of a sample of 350 long-period M, S and C Mira and semi-regular variable stars have been investigated. We compare M, S and C Mira and semi-regular stars, present a classification of the light curves of LPVs and give discriminant parameters.

scholarly journals AUTOMATED CLASSIFICATION OF VARIABLE STARS IN THE ASTEROSEISMOLOGY PROGRAM OF THE KEPLER SPACE MISSION

2010 ◽  
Vol 713 (2) ◽  
pp. L204-L207 ◽  
Author(s):  
J. Blomme ◽  
J. Debosscher ◽  
J. De Ridder ◽  
C. Aerts ◽  
R. L. Gilliland ◽  
...  
Keyword(s):  
Space Mission ◽  
Variable Stars ◽  
Automated Classification

scholarly journals Classification of variable stars in the WFCAM Transit Survey

2013 ◽  
Vol 47 ◽  
pp. 01007 ◽  
Author(s):  
Hristo Stoev ◽  
David Barrado ◽  
Luis M. Sarro ◽  
Andrés Moya
Keyword(s):  
Variable Stars
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