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- ID:
- ivo://svo.cab/cat/wdw1
- Title:
- The SVO archive of White Dwarfs from Gaia
- Short Name:
- White dwarfs (1)
- Date:
- 03 Jun 2020 15:32:02
- Publisher:
- SVO/CAB
- Description:
- The SVO archive of White Dwarfs from Gaia
- ID:
- ivo://svo.cab/cat/wdw3
- Title:
- The SVO archive of white dwarfs from Gaia (3)
- Short Name:
- White dwarfs (3)
- Date:
- 03 Jun 2020 08:05:06
- Publisher:
- SVO/CAB
- Description:
- The SVO archive of white dwarfs from Gaia
- ID:
- ivo://svo.cab/cat/ucd_jplus
- Title:
- The SVO-JPLUS archive of ultracool dwarfs
- Short Name:
- SVO-JPLUS-UCD
- Date:
- 11 Jun 2020 10:22:13
- Publisher:
- SVO/CAB
- Description:
- This data server provides access to 210 candidate ultracool dwarfs identified using J-PLUS (IDR201709) and the Virtual Observatory.
- ID:
- ivo://svo.cab/ltsa
- Title:
- The SVO late-type subdwarf archive
- Short Name:
- SVO-LTSA
- Date:
- 11 Jun 2020 09:42:34
- Publisher:
- SVO/CAB
- Description:
- This data server provides access to the SVO late-type subdwarf catalogue compiled by Lodieu et al. (2016, submitted). It contains 171 late-type subdwarf candidates obtained after a literature search.
- ID:
- ivo://CDS.VizieR/J/AJ/161/170
- Title:
- The Swan: an approach to derive surface gravity
- Short Name:
- J/AJ/161/170
- Date:
- 20 Jan 2022
- Publisher:
- CDS
- Description:
- Stellar light curves are well known to encode physical stellar properties. Precise, automated, and computationally inexpensive methods to derive physical parameters from light curves are needed to cope with the large influx of these data from space-based missions such as Kepler and TESS. Here we present a new methodology that we call "The Swan", a fast, generalizable, and effective approach for deriving stellar surface gravity (logg) for main-sequence, subgiant, and red giant stars from Kepler light curves using local linear regression on the full frequency content of Kepler long-cadence power spectra. With this inexpensive data-driven approach, we recover logg to a precision of ~0.02dex for 13822 stars with seismic logg values between 0.2 and 4.4dex and ~0.11dex for 4646 stars with Gaia-derived logg values between 2.3 and 4.6dex. We further develop a signal-to-noise metric and find that granulation is difficult to detect in many cool main-sequence stars (Teff<~5500K), in particular K dwarfs. By combining our logg measurements with Gaia radii, we derive empirical masses for 4646 subgiant and main-sequence stars with a median precision of ~7%. Finally, we demonstrate that our method can be used to recover logg to a similar mean absolute deviation precision for a TESS baseline of 27days. Our methodology can be readily applied to photometric time series observations to infer stellar surface gravities to high precision across evolutionary states.
- ID:
- ivo://CDS.VizieR/J/ApJS/209/14
- Title:
- The Swift/BAT hard X-ray transient monitor
- Short Name:
- J/ApJS/209/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Swift/Burst Alert Telescope (BAT) hard X-ray transient monitor provides near real-time coverage of the X-ray sky in the energy range 15-50 keV. The BAT observes 88% of the sky each day with a detection sensitivity of 5.3 mCrab for a full-day observation and a time resolution as fine as 64s. The three main purposes of the monitor are (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the flux of known X-ray sources, and (3) the generation of light curves of more than 900 sources spanning over eight years. The primary interface for the BAT transient monitor is a public Web site. Between 2005 February 12 and 2013 April 30, 245 sources have been detected in the monitor, 146 of them persistent and 99 detected only in outburst. Among these sources, 17 were previously unknown and were discovered in the transient monitor. In this paper, we discuss the methodology and the data processing and filtering for the BAT transient monitor and review its sensitivity and exposure. We provide a summary of the source detections and classify them according to the variability of their light curves. Finally, we review all new BAT monitor discoveries. For the new sources that are previously unpublished, we present basic data analysis and interpretations.
22088. The SWIRE Data Service
- ID:
- ivo://jvo/swire
- Title:
- The SWIRE Data Service
- Short Name:
- SWIRE
- Date:
- 05 Oct 2019 08:47:54
- Publisher:
- JVO
- Description:
- The Spitzer Wide-area InfraRed Extragalactic survey is one of six very large programs undertaken as Legacy surveys during the first year of the Spitzer Space Observatory. SWIRE has imaged nearly 50 square degrees (equal to the area of 250 full moons) divided among 6 different directions on the sky, detecting over 2 million galaxies by their heat radiation, some of them over 11 billion light years away.
- ID:
- ivo://CDS.VizieR/J/AN/341/989
- Title:
- theta Cep radial velocity curve
- Short Name:
- J/AN/341/989
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In 2015 a radial velocity monitoring campaign was started in order to redetermine and/or constrain the orbital solutions of spectroscopic binary systems. The observations were carried out at the University Observatory Jena with the echelle spectrograph FLECHAS. The results from the main part of our target sample are already published. For the final target of this campaign, theta Cep, we can now present an orbital solution based on a homogeneously covered radial velocity curve. The period of this single-lined spectroscopic binary turns out to be significantly larger and the orbit is much more eccentric compared to the given values in the 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix et al., Cat. B/sb9).
- ID:
- ivo://CDS.VizieR/J/A+A/506/1469
- Title:
- theta Cyg radial velocity variations
- Short Name:
- J/A+A/506/1469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the frame of the search for extrasolar planets and brown dwarfs around early-type main-sequence stars, we present the results obtained on the early F-type star theta Cygni. ELODIE and SOPHIE at Observatoire de Haute-Provence (OHP) were used to obtain 91 and 162 spectra, respectively. Our dedicated radial-velocity measurement method was used to monitor the star's radial velocities over five years. We also use complementary, high angular resolution and high-contrast images taken with PUEO at CFHT. We show that theta Cygni radial velocities are quasi-periodically variable, with a ~150-day period. These variations are not due to the ~0.35M_{sun}_ stellar companion that we detected in imaging at more than 46AU from the star. The absence of correlation between the bisector velocity span variations and the radial velocity variations for this 7km/s vsini star, as well as other criteria indicate that the observed radial velocity variations are not due to stellar spots. The observed amplitude of the bisector velocity span variations also seems to rule out stellar pulsations. However, we observe a peak in the bisector velocity span periodogram at the same period as the one found in the radial velocity periodogram, which indicates a probable link between these radial velocity variations and the low amplitude lineshape variations which are of stellar origin. Long-period variations are not expected from this type of star to our knowledge. If a stellar origin (hence of new type) was to be confirmed for these long-period radial velocity variations, this would have several consequences on the search for planets around main-sequence stars, both in terms of observational strategy and data analysis. An alternative explanation for these variable radial velocities is the presence of at least one planet of a few Jupiter masses orbiting at less than 1AU; however this planet alone does not explain all observed features, and the theta Cygni system is obviously more complex than a planetary system with 1 or 2 planets. The available data do not allow to distinguish between these two possible origins. A vigourous follow-up in spectroscopy and photometry is needed to get a comprehensive view of the star intrinsic variability and/or its surrounding planetary system.
