- ID:
- ivo://CDS.VizieR/J/A+A/557/A1
- Title:
- Bright B-type variables in Scorpius
- Short Name:
- J/A+A/557/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The first two of a total of six nano-satellites that will constitute the BRITE-Constellation space photometry mission have recently been launched successfully. In preparation for this project, we carried out time-resolved colour photometry in a field that is an excellent candidate for BRITE measurements from space. We acquired 117h of Stromgren uvy data during 19 nights. Our targets comprised the {beta} Cephei stars {kappa} and {lambda} Sco, the eclipsing binary {mu}^1^ Sco, and the variable super/hypergiant {zeta}^1^ Sco. For {kappa} Sco, a photometric mode identification in combination with results from the spectroscopic literature suggests a dominant (l,m)=(1,-1) {beta} Cephei-type pulsation mode of the primary star. The longer period of the star may be a rotational variation or a g-mode pulsation. For {lambda} Sco, we recover the known dominant {beta} Cephei pulsation, a longer-period variation, and observed part of an eclipse. Lack of ultraviolet data precludes mode identification for this star. We noticed that the spectroscopic orbital ephemeris of the closer pair in this triple system is inconsistent with eclipse timings and propose a refined value for the orbital period of the closer pair of 5.95189+/-0.00003d. We also argue that the components of the {lambda} Sco system are some 30% more massive than previously thought. The binary light curve solution of {mu}^1^ Sco requires inclusion of the irradiation effect to explain the u light curve, and the system could show additional low amplitude variations on top of the orbital light changes. {zeta}^1^ Sco shows long-term variability on a time scale of at least two weeks that we prefer to interpret in terms of a variable wind or strange mode pulsations.
« Previous |
1 - 10 of 39
|
Next »
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/158/193
- Title:
- Catalog of Galactic {beta} Cephei stars
- Short Name:
- J/ApJS/158/193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an extensive and up-to-date catalog of Galactic {beta} Cephei stars. This catalog is intended to give a comprehensive overview of observational characteristics of all known {beta} Cephei stars, covering information until 2004 June. Ninety-three stars could be confirmed to be {beta} Cephei stars. We use data from more than 250 papers published over the last nearly 100 years, and we provide over 45 notes on individual stars. For some stars we reanalyzed published data or conducted our own analyses. Sixty-one stars were rejected from the final {beta} Cephei list, and 77 stars are suspected to be {beta} Cephei stars. A list of critically selected pulsation frequencies for confirmed {beta} Cephei stars is also presented.
- ID:
- ivo://CDS.VizieR/J/MNRAS/431/2106
- Title:
- CU Vir Stroemgren differential photometry
- Short Name:
- J/MNRAS/431/2106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to measure the variations of the magnetic chemically peculiar star CU Vir, we obtained 2821 good Stroemgren uvby photometric values from the Four College Automated Photometric Telescope in the period 1998-2012 and 5529 values from the Solar Mass Ejection Imager in the period 2003-2006, allowing us to further clarify the situation concerning its rotational period, described previously by Pyper et al. (1998A&A...339..822P). Our main result is that the O-C data since 1993 are consistent with a constant period of 0.5207137+/-0.0000010d, which is longer than the period 0.52070308d of Pyper et al. (1998A&A...339..822P). The data during the time period 1993-2012 show no evidence of glitches. The data between 1987 and 1993 correspond to a shorter period of 0.520701d, and the inclusion of those data in the previous study made the published period come out shorter. We also cannot rule out a constantly lengthening period if the data since 1987 are included; however, the fit is slightly better for a constant period. At least five more years of consistent data will be required to distinguish between these two models. Radio astronomy data published since 1998 show phase shifts in the radio emission peaks that are inconsistent with the rotation period inferred from the optical photometry. These shifts may be due to instabilities in the region where the radio emissions originate; they indicate that the photosphere and the upper atmosphere are not rigidly coupled.
- ID:
- ivo://CDS.VizieR/J/other/JAD/18.2
- Title:
- CY Aqr multiband photometry: 2011 season
- Short Name:
- J/other/JAD/18.2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on more than a dozen partial nights of filterless CCD photometry combined with Stromgren uvby photomultiplier photometry, we derive 29 new times of maximum light of the SX Phoenicis star CY Aquarii. These times support a linear ephemeris for 2003-2011. In addition, we present uvby light curves for this star. Our dataset displays the smallest residual spread compared to any other substantial dataset published during the last decade.
- ID:
- ivo://CDS.VizieR/J/A+AS/144/469
- Title:
- Delta Scuti stars
- Short Name:
- J/A+AS/144/469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An extensive and up-dated list of {delta} Sct stars is presented here. More than 500 papers, published during the last few years, have been revised and 341 new variables have been added to our last list, six years ago. This catalogue is intended to be a comprehensive review on the observational characteristics of all the {delta} Sct stars known until now, including stars contained in earlier catalogues together with other new discovered variables, covering information published until January 2000. In summary, 636 variables, 1149 references and 182 individual notes are presented in this new list.
- ID:
- ivo://CDS.VizieR/J/A+A/476/881
- Title:
- Differential photometry of FK Com
- Short Name:
- J/A+A/476/881
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the present work we publish new photometric observations of the very active single giant, FK Com for the time period between the 1st of January 2002 and the 8th of July 2004. The observations have been carried out with three different automatic photometric telescopes: Phoenix 10, Wolfgang and Amadeus, all located in Arizona, USA. Observations contain measurements at the following bands: Johnson U, B and V, Cousins I and Stroemgren b and y. The observations are differential photometry in respect to the primary comparison star HD 117567.
- ID:
- ivo://CDS.VizieR/J/AJ/129/2026
- Title:
- Differential photometry of HD 8801
- Short Name:
- J/AJ/129/2026
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have discovered the first example of a star pulsating intrinsically with both {gamma} Doradus and {delta} Scuti frequencies. HD 8801 is an Am metallic-line star that appears to be single. Since the vast majority of Am stars are members of binary systems with periods less than 1000 days and also do not pulsate, HD 8801 possesses a very unusual, if not unique, combination of physical properties. Our photometry, acquired with an automatic telescope at Fairborn Observatory, resolves six independent pulsation periods between 0.048 and 0.404 days. The two longest periods lie within the range of {gamma} Dor variables, while the four shorter periods are within the range of {delta} Sct stars.
- ID:
- ivo://CDS.VizieR/J/A+A/456/261
- Title:
- Differential uvby photometry of HD 239276
- Short Name:
- J/A+A/456/261
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The variability of HD 239276 was suspected photometrically nearly twenty years ago, but was confirmed with new observations obtained in 2001 during a two-site photometric campaign carried out from Spain, in uvby{beta} Stroemgren-Crawford photometry, and China, using the Johnson V filter. Two low-dispersion spectra were also collected. The results establish this star as a new multiperiodic gamma Dor-type pulsator with deficiency in metallicity.
- ID:
- ivo://CDS.VizieR/J/A+A/450/715
- Title:
- Differential uvby photometry of HD 218427
- Short Name:
- J/A+A/450/715
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 1 contents 845 simultaneous measurements collected in each of the four uvby colours of the Stromgren photometric system for the Gamma Doradus variable HD 218427. The data are magnitude differences (Du, Dv, Db, Dy, D(b-y), Dm1, Dc1) of the variable star minus comparison star in the standard system versus Heliocentric Julian Date. The comparison star is HD 219874. The origin in time is the Julian Day 2452839. The observations were carried out by the authors through the year 2003 using the 0.90m telescope at Sierra Nevada Observatory, Spain (Julian Days:0 to 69 in the table) and the 1.50m telescope at San Pedro Martir Observatory, Mexico (Julian Days: 122 to 128). Both telescopes are equipped with identical six-channel uvby-Hbeta spectrograph photometers for simultaneous measurements in uvby or in the narrow and wide H{beta} channels, respectively. Please note that a technical problem arose with the "u" filter in the 1.50m telescope, which made the "u" data collected with that telescope useless and they are named as 99.
- ID:
- ivo://CDS.VizieR/J/A+A/309/787
- Title:
- DX Eri variability
- Short Name:
- J/A+A/309/787
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of nearly simultaneous monitoring of uvby light and HeI667.81nm line-profile variations of the equatorial Be star DX Eri in November 1991. They are analysed along with numerous uvby photometry in the period 1986-1995.
- « Previous
- Next »
- 1
- 2
- 3
- 4
