- ID:
- ivo://CDS.VizieR/J/MNRAS/392/1456
- Title:
- VIc photometry of M50 (NGC 2323) low-mass stars
- Short Name:
- J/MNRAS/392/1456
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the results of a time-series photometric survey of M50 (NGC 2323), a ~130Myr open cluster, carried out using the Cerro Tololo Inter-American Observatory (CTIO) 4-m Blanco telescope and Mosaic-II detector as part of the Monitor project. Rotation periods were derived for 812 candidate cluster members over the mass range 0.2<=M/M_{sun}_<=1.1. The rotation period distributions show a clear mass-dependent morphology, statistically indistinguishable from those in NGC 2516 and M35 taken from the literature. Due to the availability of data from three observing runs separated by ~10 and 1 month time-scales, we are able to demonstrate clear evidence for evolution of the photometric amplitudes, and hence spot patterns, over the 10 month gap. We are not able to constrain the time-scales for these effects in detail due to limitations imposed by the large gaps in our sampling, which also prevent the use of the phase information.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/377/741
- Title:
- VIc photometry of NGC 2516
- Short Name:
- J/MNRAS/377/741
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the results of an i-band time-series photometric survey of NGC2516 using the Cerro Tololo Inter-American Observatory (CTIO) 4-m Blanco telescope and 8k Mosaic-II detector, achieving better than 1 per cent photometric precision per data point over 15<~i<~19. Candidate cluster members were selected from a V versus V-I colour-magnitude diagram over 16<V<26 (covering masses from 0.7M_{sun}_ down to below the brown dwarf limit), finding 1685 candidates, of which we expect ~1000 to be real cluster members, taking into account contamination from the field (which is most severe at the extremes of our mass range). Searching for periodic variations in these gave 362 detections over the mass range 0.15<~M/M_{sun}_<~0.7. The rotation period distributions were found to show a remarkable morphology as a function of mass, with the fastest rotators bounded by P>0.25d, and the slowest rotators for M<~0.5M_{sun}_ bounded by a line of P~M3, with those for M>~0.5M_{sun}_ following a flatter relation closer to P ~ constant. Models of the rotational evolution were investigated, finding that the evolution of the fastest rotators was well reproduced by a conventional solid body model with a mass-dependent saturation velocity, whereas core-envelope decoupling was needed to reproduce the evolution of the slowest rotators. None of our models were able to simultaneously reproduce the behaviour of both populations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/383/1588
- Title:
- VIc photometry of NGC 2547 low-mass stars
- Short Name:
- J/MNRAS/383/1588
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the results of an I-band time-series photometric survey of NGC 2547 using the MPG/ESO 2.2-m telescope with Wide Field Imager, achieving better than 1 per cent photometric precision per data point over 14~<I~<18. Candidate cluster members were selected from a V versus V-I colour-magnitude diagram over 12.5<V<24 (covering masses from 0.9M_{sun}_ down to below the brown dwarf limit), finding 800 candidates, of which we expect ~330 to be real cluster members, taking into account contamination from the field (which is most severe at the extremes of our mass range). Searching for periodic variations in these gave 176 detections over the mass range 0.1~<M/M_{sun}_<0.9.
- ID:
- ivo://CDS.VizieR/J/AcA/57/249
- Title:
- VIc photometry of NGC 6755 stars
- Short Name:
- J/AcA/57/249
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a search for variable stars in the field of a young open cluster NGC 6755. Altogether seventy one variable stars have been discovered. Thirty one of them are eclipsing systems. This group contains ten EA, four EB and seventeen EW-type systems. Photometric variability of four late type stars is most probably caused by their chromospherical activity. Another seven detected variable stars have light curves typical for pulsating stars from the main instability strip. Four of them we tentatively classified as gamma Dor, one as delta Sct and two as Population II Cepheid variable stars, respectively. Star designated as V40 can be either another population II Cepheid or an ellipsoidal binary system. The remaining twenty eight variable stars found in the field of this open cluster are most probably highly obscured background red giants (OSARG, irregular). For all detected variable stars we provide their light curves, preliminary classification, discussion on the possible cluster membership, equatorial coordinates, finding charts and periods when possible.
- ID:
- ivo://CDS.VizieR/J/A+A/515/A100
- Title:
- VI light curves of NGC 1039 solar-type stars
- Short Name:
- J/A+A/515/A100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Employing photometric rotation periods for solar-type stars in NGC 1039 [M 34], a young, nearby open cluster, we use its mass-dependent rotation period distribution to derive the cluster's age in a distance independent way, i.e., the so-called gyrochronology method. We present an analysis of 55 new rotation periods, using light curves derived from differential photometry, for solar type stars in the open cluster NGC 1039 [M 34]. We also exploit the results of a recently-completed, standardized, homogeneous BVIc CCD survey of the cluster, performed by the Indiana Group of the WIYN open cluster survey, in order to establish photometric cluster membership and assign B-V colours to each photometric variable. We describe a methodology for establishing the gyrochronology age for an ensemble of solar-type stars. Empirical relations between rotation period, photometric colour and stellar age (gyrochronology) are used to determine the age of M 34.
- ID:
- ivo://CDS.VizieR/J/BaltA/13/555
- Title:
- Vilnius photometry in NGC 2395
- Short Name:
- J/BaltA/13/555
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The area of the open cluster NGC 2395 in Gemini is investigated by CCD photometry in the Vilnius seven-color system. Magnitudes, color indices, photometric spectral types, color excesses, interstellar extinctions and distances are determined for the 163 stars down to V=15.75mag in the 25' diameter area.
- ID:
- ivo://CDS.VizieR/J/BaltA/21/465
- Title:
- Vilnius photometry in NGC7129 and NGC7142
- Short Name:
- J/BaltA/21/465
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In a 1.5 square degree area, centered at RA=21:44:30, DE=+65:58, we have determined magnitudes and color indices for 2140 stars in the Vilnius seven-color system down to V=17mag. This area includes a star-forming region with the open cluster NGC 7129 embedded in a dense dust cloud TGU 645 (LDN 1181), close to the Cepheus Flare, and a distant old open cluster NGC 7142 seen through a semi-transparent window. For most of the stars spectral and luminosity classes in the MK system, determined from the photometric data, are given.
- ID:
- ivo://CDS.VizieR/J/A+A/554/A3
- Title:
- Vilnius photometry of IC1805 stars
- Short Name:
- J/A+A/554/A3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of CCD photometry in the Vilnius seven-color system down to V=18mag are presented for 242 stars in the direction of the young open cluster IC 1805 that is located in the active star-forming region W4 in the Cas OB6 association. Photometric data were used to classify stars into spectral and luminosity classes, and to determine their interstellar reddenings, extinctions and distances.
- ID:
- ivo://CDS.VizieR/J/BaltA/22/181
- Title:
- Vilnius photometry of M29 (NGC6913)
- Short Name:
- J/BaltA/22/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Magnitudes and color indices in the Vilnius seven-color system were determined for 1752 stars down to V = 19.5 mag in the direction of the open cluster M29 (NGC 6913). The region is centered at RA=20:24, DEC=+38:30 (J2000) and covers an area of 1.5 sq. deg. The photometric data are used to classify about 70% of stars in spectral and luminosity classes and peculiarity types.
- ID:
- ivo://CDS.VizieR/J/BaltA/14/179
- Title:
- Vilnius photometry of NGC 1647 area
- Short Name:
- J/BaltA/14/179
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The area of the open cluster NGC 1647 in Taurus is investigated by CCD photometry in the Vilnius seven-color system. Magnitudes and color indices are determined for 433 stars down to V=15.0mag in the 45arcmin diameter area. For 252 of them photometric spectral and luminosity classes, interstellar reddenings, extinctions and distances are obtained. According to the CDS WEBDA database, 89 of them have a high cluster membership probability. Their mean distance from the Sun is 555+/-74pc, excluding four stars which seem to be field stars. The main sequence starts at spectral class B7 V which corresponds to a cluster age of about 150 million years. Cluster members show a differential interstellar extinction ranging from 0.8 to 1.8mag. The mean extinction of the cluster stars is 1.12+/-0.25mag. Interstellar extinction in the area is dominated by the Taurus dark cloud complex at 160pc. Color excesses of individual stars correlate well with the 100um dust thermal emission intensity. The cluster shape is investigated by counting stars down to K=15.6mag and is found to be elongated in the direction roughly perpendicular to the Milky Way, with the flattening 0.4.
