- ID:
- ivo://CDS.VizieR/J/other/IBVS/6106
- Title:
- RR Lyrae stars in GCVS observed by the QES
- Short Name:
- J/other/IBVS/610
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used the light curve archive of the Qatar Exoplanet Survey to investigate the RR Lyrae variable stars listed in the GCVS. Of 588 variables studied, we reclassified 14 as eclipsing binaries, one as an RS CVn type variable, one as an irregular variable, four as classical Cepheids, and one as a type II Cepheid, while also improving their periods. We also report new RR Lyrae sub-type classifications for 65 variables and improve on the GCVS period estimates for 135 RR Lyrae variables. There are seven double-mode RR Lyrae stars in the sample for which we measured their fundamental and first overtone periods. Finally, we detected the Blazhko effect in 38 of the RR Lyrae stars for the first time and we successfully measured the Blazhko period for 26 of them.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/808/11
- Title:
- RR Lyrae stars in M4. II. Spitzer/IRAC phot.
- Short Name:
- J/ApJ/808/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New mid-infrared (MIR) period-luminosity (PL) relations are presented for RR Lyrae variables in the globular cluster M4 (NGC 6121). Accurate photometry was obtained for 37 RR Lyrae variables using observations from the Infrared Array Camera on board the Spitzer Space Telescope. The dispersion of M4's PL relations is 0.056, and the uncertainty in the slope is 0.11mag. Additionally, we established calibrated PL relations at 3.6 and 4.5{mu}m using published Hubble Space Telescope geometric parallaxes of five Galactic RR Lyrae stars. The resulting band-averaged distance modulus for M4 is {mu}=11.399+/-0.007(stat)+/-0.080(syst)+/-0.015(cal)+/-0.020(ext). The systematic uncertainty will be greatly reduced when parallaxes of more stars become available from the GAIA mission. Optical and infrared period-color (PC) relations are also presented, and the lack of an MIR PC relation suggests that RR Lyrae stars are not affected by CO absorption in the 4.5{mu}m band.
- ID:
- ivo://CDS.VizieR/J/AJ/109/618
- Title:
- RR Lyrae Stars in NGC 5053
- Short Name:
- J/AJ/109/618
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The RR Lyrae stars in NGC 5053 are investigated using B,V photometry derived from CCD frames taken on 15 nights between 1985 and 1994. Estimates of fundamental photometric parameters are presented for the ten stars, including mean B and V magnitudes, pulsation periods, pulsation amplitudes, <B>-<V> colors, and period change rates. Until now the mean B,V magnitudes were unknown because the previous photographic photometry by Baade [Mitteilungen der Hamburger, Sternwarte, B6, n.29 (1928)], Sawyer [Pub. DDO 1, No. 18, p. 357 (1946)], Rosino [MSAIt, 20, 3 (1949)], and Mannino [Pub. Obs. Bologna, 8, No. 12 (1963)] is not on the Johnson system and is not readily transformed to that system.
- ID:
- ivo://CDS.VizieR/J/AJ/141/171
- Title:
- RR Lyrae stars in six ultra-deep fields of M31
- Short Name:
- J/AJ/141/171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present HST/ACS observations of RR Lyrae variable stars in six ultra-deep fields of the Andromeda galaxy (M31), including parts of the halo, disk, and giant stellar stream. Past work on the RR Lyrae stars in M31 has focused on various aspects of the stellar populations that make up the galaxy's halo, including their distances and metallicities. This study builds upon this previous work by increasing the spatial coverage (something that has been lacking in previous studies) and by searching for these variable stars in constituents of the galaxy not yet explored.
- ID:
- ivo://CDS.VizieR/J/ApJ/765/154
- Title:
- RR Lyrae stars in the Catalina Sky Survey
- Short Name:
- J/ApJ/765/154
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of 1207 RR Lyrae found in photometry taken by the Catalina Survey's Mount Lemmon telescope. By combining accurate distances for these stars with measurements for ~14000 type-ab RR Lyrae from the Catalina Schmidt telescope, we reveal an extended association that reaches Galactocentric distances beyond 100kpc and overlaps the Sagittarius stream system. This result confirms earlier evidence for the existence of an outer halo tidal stream resulting from a disrupted stellar system. By comparing the RR Lyrae source density with that expected based on halo models, we find the detection has ~8{sigma} significance. We investigate the distances, radial velocities, metallicities, and period-amplitude distribution of the RR Lyrae. We find that both radial velocities and distances are inconsistent with current models of the Sagittarius stream. We also find tentative evidence for a division in source metallicities for the most distant sources. Following prior analyses, we compare the locations and distances of the RR Lyrae with photometrically selected candidate horizontal branch stars and find supporting evidence that this structure spans at least 60{deg} of the sky. We investigate the prospects of an association between the stream and the unusual globular cluster NGC 2419.
- ID:
- ivo://CDS.VizieR/J/A+A/375/909
- Title:
- RR Lyrae stars in the Sgr dwarf
- Short Name:
- J/A+A/375/909
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out a period analysis on ~3700 RR Lyrae stars on two Schmidt fields centred on (l, b)=(3.1{deg}, -77.1{deg}) and (6.6{deg}, -10.8{deg}) respectively, covering an area of ~50{deg}^2^. These stars are distributed almost evenly between the Sagittarius dwarf galaxy (Sgr) and the Milky Way. Files in the "lcurves" directory are the light curves of the multi-periodic RR Lyraes discovered towards the Sgr dwarf galaxy. This set includes stars in Sgr and also foreground Galactic RR Lyraes.
- ID:
- ivo://CDS.VizieR/J/A+A/357/871
- Title:
- RR Lyrae stars in the Sgr dwarf galaxy
- Short Name:
- J/A+A/357/871
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out a search for RR Lyrae stars towards the Sagittarius dwarf galaxy based on two series of photographic Schmidt plates. This search yielded 4013 RR Lyrae stars (3947 mono-periodic, and 66 multi-periodic) spread over ~50 square degrees between Galactic latitudes b=-4{deg} and b=-15{deg}. The analysis of this catalog of RR Lyraes allowed us to map the structure of the Sagittarius dwarf galaxy behind the high density of Galactic foreground stars (this paper, Paper I), and to study the properties of the old stellar population in the Sgr dwarf (Paper II, Cseresnjes, 2001, Cat. <J/A+A/375/909>).
- ID:
- ivo://CDS.VizieR/J/ApJ/678/851
- Title:
- RR Lyrae survey in the Galactic Halo
- Short Name:
- J/ApJ/678/851
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a search for RR Lyrae variable stars from archival observations of the Southern Edgeworth-Kuiper Belt Object survey. The survey covers 1675deg^2^ along the ecliptic to a mean depth of V=19.5, i.e., a heliocentric distance of ~50kpc for RR Lyrae stars. The survey reveals 2016 RR Lyrae candidates. Follow-up photometric monitoring of a subset of these candidates shows ~24% contamination by non-RR Lyrae variables. We derive a map of overdensity of RR Lyrae stars in the halo that reveals a series of structures coincident with the leading and trailing arms of debris from the Sagittarius dwarf galaxy. One of the regions of overdensity is found on the trailing arm, 200{deg} from the main body of the Sagittarius dwarf at a distance of ~45kpc. This distant detection of the stellar population of the outer trailing arm of Sagittarius offers a tight constraint on the motion of the dwarf galaxy. A distinctly separate region of overdensity is seen toward the Virgo overdensity.
- ID:
- ivo://CDS.VizieR/J/ApJ/784/76
- Title:
- RR Lyrae variables in ESO294-G010 and ESO410-G005
- Short Name:
- J/ApJ/784/76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of our analysis of the RR Lyrae (RRL) variable stars detected in two transition-type dwarf galaxies (dTrans), ESO294-G010 and ESO410-G005 in the Sculptor group, which is known to be one of the closest neighboring galaxy groups to our Local Group. Using deep archival images from the Advanced Camera for Surveys on board the Hubble Space Telescope, we have identified a sample of RRL candidates in both dTrans galaxies (219 RRab (RR0) and 13 RRc (RR1) variables in ESO294-G010; 225 RRab and 44 RRc stars in ESO410-G005). The metallicities of the individual RRab stars are calculated via the period-amplitude-[Fe/H] relation derived by Alcock et al. This yields mean metallicities of <[Fe/H]>_ESO294_=-1.77+/-0.03 and <[Fe/H]>_ESO410_=-1.64+/-0.03. The RRL metallicity distribution functions (MDFs) are investigated further via simple chemical evolution models; these reveal the relics of the early chemical enrichment processes for these two dTrans galaxies. In the case of both galaxies, the shapes of the RRL MDFs are well described by pre-enrichment models. This suggests two possible channels for the early chemical evolution for these Sculptor group dTrans galaxies: (1) the ancient stellar populations of our target dwarf galaxies might have formed from the star forming gas which was already enriched through "prompt initial enrichment" or an "initial nucleosynthetic spike" from the very first massive stars, or (2) this pre-enrichment state might have been achieved by the end products from more evolved systems of their nearest neighbor, NGC 55. We also study the environmental effects of the formation and evolution of our target dTrans galaxies by comparing their properties with those of 79 volume limited (D_{sun}_<2Mpc) dwarf galaxy samples in terms of the luminosity-metallicity relation and the H I gas content. The presence of these RRL stars strongly supports the idea that although the Sculptor Group galaxies have a considerably different environment from the Local Group (e.g., no giant host galaxies, loosely bound and very low local density), they share a common epoch of early star formation with the dwarf satellite galaxies in the Local Group.
- ID:
- ivo://CDS.VizieR/J/AJ/138/184
- Title:
- RR Lyrae variables in 2 fields in M31 spheroid
- Short Name:
- J/AJ/138/184
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Hubble Space Telescope observations taken with the Advanced Camera for Surveys Wide Field Channel of two fields near M32 - between 4 and 6kpc from the center of M31. The data cover a time baseline sufficient for the identification and characterization of 681 RR Lyrae variables of which 555 are ab-type and 126 are c-type.
