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3661. Long-term photometry of 11 RS CVn stars
ID:
ivo://CDS.VizieR/J/other/JAD/18.5
Title:
Long-term photometry of 11 RS CVn stars
Short Name:
J/other/JAD/18.5
Date:
21 Oct 2021
Publisher:
CDS
Description:
I present BVRI photometry of short-period (P<1d) eclipsing RS CVn binary star systems collected between 1988 and 2009 at Mount Laguna Observatory. Most of the data are for ER Vul and WY Cnc, with light curves nearly every year during that time period. I also present light curves for at least several years for XY UMa, BH Vir, CG Cyg, RT And, and UV Psc. I have fewer light curves for SV Cam, UV Leo, 1E1919+0427, and GSC 2038-0293. In addition to the eclipsing short-period systems, I also include UBVRI data for two longer period non-eclipsing RS CVn binary systems: UZ Lib and DM UMa, as well as two active chromosphere single stars: FK Com and HD 199178.
3662. Long-term photometry of Variables I.
ID:
ivo://CDS.VizieR/II/170
Title:
Long-term photometry of Variables I.
Short Name:
II/170
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the first catalogue of photometric data in the Stroemgren system obtained during the period October 1982 - September 1986. Full description can be found in ESO report SP 8. Since our goal is not absolute (all-sky) photometry, the observations should be used for differential photometry only. The mean values of the r.m.s. deviations of the differential measurements of comparison stars are around (from Table 5 of paper) ------------------------------------ System y b-y m1 c1 ------------------------------------ 1 0.0109 0.0088 0.0133 0.0136 4 0.0068 0.0057 0.0079 0.0118 5 0.0087 0.0070 0.0114 0.0114 6 0.0090 0.0078 0.0126 0.0132 7 0.0071 0.0033 0.0041 0.0065 ------------------------------------
3663. Long-term photometry of Variables II
ID:
ivo://CDS.VizieR/II/188
Title:
Long-term photometry of Variables II
Short Name:
II/188
Date:
21 Oct 2021
Publisher:
CDS
Description:
The second catalogue of the LTPV programme contains photometric data obtained during the period October 1986 - September 1990. Full description can be found in ESO reports SP 8 and 12. The data presented here have been upgraded since the printing of catalogue ESO SR 12; a major change is the use of a quite different standard, namely the ESO SAT (Stroemgren Automatic Telescope) instrumental system has been used as standard. The instrumental systems 6 and 8 can be obtained by applying the following color matrices (see ESO SR 12, page 4, Eq. (3)), inverted (b-y , y , m1 , c1): SYSTEM 6 1.0518 0.0000 0.0000 0.0000 0.0094 1.0000 0.0000 0.0000 -0.1238 0.0000 1.1206 0.0000 0.0426 0.0000 0.0000 1.0352 SYSTEM 8 1.0476 0.0000 0.0000 0.0000 0.0384 1.0000 0.0000 0.0000 -0.0877 0.0000 1.0487 0.0000 -0.2657 0.0000 0.0000 0.9732 It also very easy to go back to the same standard as in ESO SR 8 by applying the transformations given in Table 3 of ESO SR 12 (page 3). Note that the faint star C7060 is not identified so far. The mean values of the r.m.s. deviations of the differential measurements of comparison stars are around (from Table 5 of paper) ------------------------------------ System y b-y m1 c1 ------------------------------------ 6 0.0069 0.0058 0.0122 0.0129 7 0.0064 0.0030 0.0039 0.0067 8 0.0068 0.0061 0.0110 0.0097 ------------------------------------
3664. Long-term photometry of Variables III
ID:
ivo://CDS.VizieR/II/200
Title:
Long-term photometry of Variables III
Short Name:
II/200
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the third catalogue of photometric data in the Stroemgren system obtained during the period October 1990-January 1992 in the framework of the Long-Term Photometry of Variables (LTPV) program at the European Southern Observatory. All data have been obtained with the Danish 50-cm telescope. The mean values of the r.m.s. deviations of the differential measurements of comparison stars are around (from Table 4 of paper) ------------------------------ y b-y m1 c1 ------------------------------ 0.005 0.002 0.004 0.006 ------------------------------
3665. Long-term photometry of Variables IV
ID:
ivo://CDS.VizieR/II/202
Title:
Long-term photometry of Variables IV
Short Name:
II/202
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the fourth catalogue of photometric data in the Stroemgren system obtained during the period June 18, 1992 - August 23, 1994 in the framework of the Long-Term Photometry of Variables (LTPV) program at the European Southern Observatory. Since our goal is not absolute (all-sky) photometry, the observations should be used for differential photometry only. The mean values of the r.m.s. deviations of the differential measurements of comparison stars are around (from Table 3 of paper) ------------------------------ y b-y m1 c1 ------------------------------ 0.005 0.002 0.004 0.007 ------------------------------
3666. Long-term Swift monitoring of WPVS 007
ID:
ivo://CDS.VizieR/J/AJ/146/78
Title:
Long-term Swift monitoring of WPVS 007
Short Name:
J/AJ/146/78
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on multi-wavelength observations of the X-ray transient Narrow Line Seyfert 1 (NLS1) galaxy WPVS007. The galaxy was monitored with Swift between 2005 October and 2013 July, after it had previously undergone a dramatic drop in its X-ray flux. For the first time, we are able to repeatedly detect this NLS1 in X-rays again. This increased number of detections in the last couple of years may suggest that the strong absorber that has been found in this active galactic nucleus (AGN) is starting to become leaky and may eventually disappear. The X-ray spectra obtained for WPVS007 are all consistent with a partial covering absorber model. A spectrum based on the data during the extreme low X-ray flux states shows that the absorption column density is of the order of 4x10^23^/cm2 with a covering fraction of 95%. WPVS007 also displays one of the strongest UV variabilities seen in NLS1s. The UV continuum variability anti-correlates with the optical/UV slope {alpha}_UV_, which suggests that the variability may be primarily due to reddening. The UV variability timescales are consistent with moving dust "clouds" located beyond the dust sublimation radius of R_sub_{approx}20lt-days. We present for the first time near-infrared JHK data of WPVS007, which reveal a rich emission-line spectrum. Recent optical spectroscopy does not indicate significant variability in the broad permitted and FeII emission lines, implying that the ionizing continuum seen by those gas clouds has not significantly changed over the last decades. All X-ray and UV observations are consistent with a scenario in which an evolving broad absorption line (BAL) flow obscures the continuum emission. As such, WPVS007 is an important target for our understanding of BAL flows in low-mass AGNs.
3667. Long-term UBVRI photometry of GM Cep
ID:
ivo://CDS.VizieR/J/other/PASA/32.11
Title:
Long-term UBVRI photometry of GM Cep
Short Name:
J/other/PASA/32.
Date:
21 Oct 2021
Publisher:
CDS
Description:
Results from UBVRI photometric observations of the pre-main sequence star GM Cephei obtained in the period April 2011 - August 2014 are reported in the paper. Presented data are a continuation of our photometric monitoring of the star started in 2008. GM Cep is located in the field of the young open cluster Trumpler 37 and over the past years it has been an object of intense photometric and spectral studies. The star shows a strong photometric variability interpreted as a possible outburst from EXor type in previous studies. Our photometric data for a period of over six years show a large amplitude variability ({Delta}V~2.3mag) and several deep minimums in brightness are observed. The analysis of the collected multicolor photometric data show the typical of UX Ori variables a colour reversal during the minimums in brightness. The observed decreases in brightness have a different shape, and evidences of periodicity are not detected. At the same time, high amplitude rapid variations in brightness typical for the classical T Tauri stars also present on the light curve of GM Cep. The spectrum of GM Cep shows the typical of classical T Tauri stars wide H alpha emission line and absorption lines of some metals. We calculate the outer radius of the H{alpha} emitting region as 10.4+/-0.5R_{sun}_ and the accretion rate as 1.8x10^-7^M_{sun}_/yr.
3668. Long-term variability of Kepler sun-like stars
ID:
ivo://CDS.VizieR/J/ApJ/851/116
Title:
Long-term variability of Kepler sun-like stars
Short Name:
J/ApJ/851/116
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photometry from the Kepler mission is optimized to detect small, short- duration signals like planet transits at the expense of long-term trends. This long-term variability can be recovered in photometry from the full-frame images (FFIs), a set of calibration data collected approximately monthly during the Kepler mission. Here we present f3, an open-source package to perform photometry on the Kepler FFIs in order to detect changes in the brightness of stars in the Kepler field of view over long time baselines. We apply this package to a sample of 4000 Sun-like stars with measured rotation periods. We find that ~10% of these targets have long-term variability in their observed flux. For the majority of targets, we find that the luminosity variations are either correlated or anticorrelated with the short-term variability due to starspots on the stellar surface. We find a transition between anticorrelated (starspot-dominated) variability and correlated (facula-dominated) variability between rotation periods of 15 and 25 days, suggesting the transition between the two modes is complete for stars at the age of the Sun. We also identify a sample of stars with apparently complete cycles, as well as a collection of short-period binaries with extreme photometric variation over the Kepler mission.
3669. Long-term variations in V471 Tau
ID:
ivo://CDS.VizieR/J/A+A/281/811
Title:
Long-term variations in V471 Tau
Short Name:
J/A+A/281/811
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
3670. LOS velocities & [Fe/H] of Pal 5 tidal stream
ID:
ivo://CDS.VizieR/J/ApJ/823/157
Title:
LOS velocities & [Fe/H] of Pal 5 tidal stream
Short Name:
J/ApJ/823/157
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present Subaru/Faint Object Camera and Spectrograph and Keck/Deep Imaging Multi-Object Spectrometer medium-resolution spectroscopy of a tidally disrupting Milky Way (MW) globular cluster Palomar 5 (Pal 5) and its tidal stream. The observed fields are located to cover an angular extent of ~17{deg} along the stream, providing an opportunity to investigate a trend in line-of-sight velocities (V_los_) along the stream, which is essential to constrain its orbit and underlying gravitational potential of the MW's dark matter halo. A spectral fitting technique is applied to the observed spectra to obtain stellar parameters and metallicities ([Fe/H]) of the target stars. The 19 stars most likely belonging to the central Pal 5 cluster have a mean V_los_ of -58.1+/-0.7km/s and metallicity [Fe/H]=-1.35+/-0.06dex, both of which are in good agreement with those derived in previous high-resolution spectroscopic studies. Assuming that the stream stars have the same [Fe/H] as the progenitor cluster, the derived [Fe/H] and V_los_ values are used to estimate the possible V_los_ range of the member stars at each location along the stream. Because of the heavy contamination of the field MW stars, the estimated V_los_ range depends on prior assumptions about the stream's V_los_, which highlights the importance of more definitely identifying the member stars using proper motion and chemical abundances to obtain unbiased information of V_los_ in the outer part of the Pal 5 stream. The models for the gravitational potential of the MW's dark matter halo that are compatible with the estimated V_los_ range are discussed.