- ID:
- ivo://CDS.VizieR/J/A+A/466/181
- Title:
- BVI photometry of Whiting 1
- Short Name:
- J/A+A/466/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recently Carraro (2005ApJ...621L..61C) drew attention to the remarkable star cluster Whiting 1, showing that it lies at about 40kpc from the Sun and is therefore unquestionably a member of the Galactic halo (l=-60.6{deg}). Its Color Magnitude Diagram (CMD) indicated that Whiting 1 is very young (~5Gyrs) for a globular cluster. It is highly likely that Whiting 1 is originated in a dwarf galaxy that has since been disrupted by the Milky Way. The main purpose of the present study is to better constrain the properties of Whiting 1, and assess whether it belongs to a stellar stream from the Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph). Deep CCD photometry in the BVI pass-band obtained with the VLT is used to improve the quality of the CMD, and provide more solid estimates of the cluster distance and age, while high resolution spectra of three evolved stars obtained at Magellan is used to derive the cluster kinematics and analyze its possible membership to the Sgr dSph. We demonstrate that - independently on the Halo model employed - Whiting 1 is part of the trailing stream of the Sgr dSph. We derive a new age estimate of 6.5^+1.0^_-0.5_Gyr, and a smaller heliocentric distance of 29.4^+1.8^_-2.0_kpc. The number of globular clusters confirmed to be members of Sgr dSph is now 6. Among these clusters, Whiting 1 is particularly interesting, being the youngest and one of the most metal rich. The existence of Whiting 1 shows how the Sgr dSph was able to form star clusters for a period at least of 6Gyr.
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- ID:
- ivo://CDS.VizieR/J/AJ/147/155
- Title:
- BV photometry in and around 5 globular clusters
- Short Name:
- J/AJ/147/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Homogeneous B, V photometry is presented for 19324 stars in and around 5 Magellanic Cloud globular clusters: NGC 1466, NGC 1841, NGC 2210, NGC 2257, and Reticulum. The photometry is derived from eight nights of CCD imaging with the Cerro Tololo Inter-American Observatory 0.9m SMARTS telescope. Instrumental magnitudes were transformed to the Johnson B, V system using accurate calibration relations based on a large sample of Landolt-Stetson equatorial standard stars, which were observed on the same nights as the cluster stars. Residual analysis of the equatorial standards used for the calibration, and validation of the new photometry using Stetson's sample of secondary standards in the vicinities of the five Large Magellanic Cloud clusters, shows excellent agreement with our values in both magnitudes and colors. Color-magnitude diagrams reaching to the main-sequence turnoffs at V~22mag, sigma-magnitude diagrams, and various other summaries are presented for each cluster to illustrate the range and quality of the new photometry. The photometry should prove useful for future studies of the Magellanic Cloud globular clusters, particularly studies of their variable stars.
- ID:
- ivo://CDS.VizieR/J/PASP/99/739
- Title:
- BV photometry in 4 fields of 47 Tuc
- Short Name:
- J/PASP/99/739
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry in B and V, taken with the RCA camera at the CTIO 4-meter telescope, is reported for 8800 stars in the field of 47 Tuc (= NGC 104 = C0021-723). Our data, reduced through the DAOPHOT code, comprise results from two long-exposure frame pairs in which the photometry extends from the cluster turnoff down to V~24, and two other short-exposure fields nearer to the cluster center which precisely define the giant and horizontal branches. Color-magnitude diagrams are presented, statistically corrected for background contamination from the Small Magellanic Cloud halo, and a composite CMD and luminosity function are constructed for the entire cluster, covering an 11-magnitude range in luminosity.
- ID:
- ivo://CDS.VizieR/J/AJ/111/1596
- Title:
- BV photometry in Fornax globulars
- Short Name:
- J/AJ/111/1596
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report new color-magnitude diagrams for Fornax globular clusters 1 and 5 where our data reaches V=24, below the horizontal branch. Using the index B-R/(B+V+R), a measure of the horizontal branch color, we find cluster 1 has a red (-0.50+/-0.10) and cluster 5 an intermediate color (-0.09+/-0.12) horizontal branch confirming the first extragalactic second parameter pair. The HB types are markedly redder than the Galactic globular clusters at [Fe/H]=-2. In globular cluster 1, we find 21 possible variable stars out of 41 horizontal branch stars. Cluster 1 has an anomalously low ratio of horizontal branch to red giant stars, which formally gives a helium abundance of 0.16<Y<0.22, depending on the assumptions used. For both clusters 1 and 5, and for the red horizontal branch in the field adjacent to cluster 5, V_HB = 21.25 +/- 0.05. We give calibrated surface brightness profiles and measure new core and tidal radii for cluster 1 of 17.6" and 104" and for cluster 5 of <2" and 91", respectively.
- ID:
- ivo://CDS.VizieR/J/AJ/121/318
- Title:
- BV photometry in NGC 5986
- Short Name:
- J/AJ/121/318
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained new CCD BV photometry of the little-studied southern Galactic globular cluster NGC 5986, including light curves of five of its RR Lyrae variables. The cluster's red giant branch bump is detected for the first time, at V=16.47 +/-0.03. We derive a reddening and true distance modulus of E(B-V)=0.29+/-0.02 and (m-M)_0_=15.15+/-0.10, respectively. The cluster's color-magnitude diagram reveals a mostly blue horizontal branch, like that of M13 or M2, and quite unlike M3; yet all of these clusters have nearly identical metallicities ([Fe/H]_CG97_=-1.35). We show that the RR Lyrae variables in NGC 5986 are about 0.2mag brighter on average than those in M3, an important exception to the often-employed, universal M_V_(RR)-[Fe/H] relation. Finally, we note that NGC 5986 contains two luminous stars with spectral types A-F, which are likely to be post-asymptotic giant branch (PAGB) objects. The V-band luminosity function of such yellow PAGB stars is a promising standard candle. We suggest that the luminosity function is sharply peaked at M_V_(PAGB)=-3.28+/-0.07.
- ID:
- ivo://CDS.VizieR/J/AJ/106/1024
- Title:
- BV photometry in NGC 288
- Short Name:
- J/AJ/106/1024
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+A/448/171
- Title:
- BV photometry of 3 globular clusters
- Short Name:
- J/A+A/448/171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Some of the Galactic outer halo globular clusters are excellent tools to probe gravitational theories in the regime of weak accelerations. The measurement of the line-of-sight velocity dispersion among stars in these clusters will differentiate between the validity of Newtonian dynamics (low velocity dispersion) and the possibility of modified Newtonian dynamics (MOND) or dark matter dominated globular clusters (high velocity dispersion). In this paper, the properties of probable member stars of the three best-case gravitational theory-testing clusters AM 1, Pal 3 and Pal 14 are presented. The member selection is based on VLT photometry in Johnson BV. The positions of the stars were determined with an accuracy of the order of <=0.2", allowing their direct use for follow-up spectroscopy. The distance, reddening, age and metallicities of the clusters were estimated from isochrone fitting. Furthermore, improved structural parameters, like central coordinates, ellipticity, half-light radius, King model core and tidal radius, are presented.
128. BV photometry of M71
- ID:
- ivo://CDS.VizieR/J/A+AS/144/227
- Title:
- BV photometry of M71
- Short Name:
- J/A+AS/144/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File table2 contains coordinates (J2000) and B,V magnitudes and B-V colours with corresponding errors of 4450 stars in a 20'x20' region centered on the globular cluster M 71 (NGC 6838). The limiting magnitude of the catalogue is about V=18.0 The observations were made in 1995 at Calar Alta Observatory.
129. BV photometry of M53
- ID:
- ivo://CDS.VizieR/J/AJ/116/1775
- Title:
- BV photometry of M53
- Short Name:
- J/AJ/116/1775
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The first large-format CCD color-magnitude diagram (CMD) in the B and V passbands is presented for the Galactic globular cluster M53 (NGC 5024). The observations consist of 40 pairs of B and V CCD frames with FWHM<1.2" in a pattern covering a 12'x13' region of M53. These frames were used to produce color-magnitude data for more than 20,000 stars from the tip of the red giant branch (RGB) to about 2 mag below the main-sequence turnoff (V~22). The CMD reveals a classic example of a metal-poor stellar system, with the horizontal branch (HB) predominantly blueward of the RR Lyrae instability strip and the relatively steep RGB. The blue HB of M53 does not show the blue tail phenomenon that is observed in M15. The relative age dating based on the color difference between the turnoff and the base of RGB reveals no significant age difference ({Delta}t<1Gyr) between M53 and M92. We have discovered 114 new blue straggler stars (BSSs) in the field of M53. The analysis of bright (V<19.39) BSSs clearly shows a bimodal radial distribution with a high frequency in the inner and outer regions but a distinct dip in the intermediate region. The distribution is similar to that found in M3, a globular cluster with a similar central density and concentration.
- ID:
- ivo://CDS.VizieR/J/AJ/118/2839
- Title:
- BV photometry of NGC 1866
- Short Name:
- J/AJ/118/2839
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new deep (down to V~24) photometry of a wide region (~6'x6') around the Large Magellanic Cloud globular cluster NGC 1866. Our sample is much larger (by more than a factor of 3) than any previous photometry and with a main sequence (MS) that may be considered complete, down to at least 3 mag below the brightest MS star; such an occurrence allows a meaningful and robust comparison with various theoretical scenarios produced by means of models computed with the evolutionary code FRANEC.
