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- ID:
- ivo://CDS.VizieR/J/AJ/130/1719
- Title:
- JHKs photometry in G305.3+0.2 cluster region
- Short Name:
- J/AJ/130/1719
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-IR (NIR) J, H, and Ks images and K-band spectroscopy of two newly discovered stellar clusters at different stages of evolution. Our spectra suggest the presence of massive young stellar objects in the heavily embedded cluster in the star-forming region near radio source G353.4-0.4 and an O5-O6V star in the cluster near radio source G305+00.2.
- ID:
- ivo://CDS.VizieR/J/AJ/139/950
- Title:
- JHKs photometry in ONC
- Short Name:
- J/AJ/139/950
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present J, H, and Ks photometry of the Orion Nebula Cluster (ONC) obtained at the CTIO/Blanco 4m telescope at Cerro Tololo with the Infrared Side Port Imager camera. From the observations we have assembled a catalog of about ~7800 sources distributed over an area of approximately 30'x40', the largest of any survey deeper than the Two Micron All Sky Survey (2MASS) in this region. The catalog provides absolute coordinates accurate to about 0.15-arcsec and 3{sigma} photometry in the 2MASS system down to J~=19.5mag, H~=18.0mag, Ks~=18.5mag, enough to detect planetary size objects 1Myr old under A_V_~=10mag of extinction at the distance of the Orion Nebula.
- ID:
- ivo://CDS.VizieR/J/AJ/124/1570
- Title:
- JHKs photometry in Praesepe
- Short Name:
- J/AJ/124/1570
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Two Micron All Sky Survey and Palomar Observatory Sky Survey photographic plates, digitized by the US Naval Observatory's Precision Measuring Machine program, to derive proper motions over a 100 square degree, spatially complete region centered on the Praesepe open cluster. Proper-motion measurements spanned the magnitude range R~12-19, which covers most of the lower main sequence in Praesepe. The incidence of H{alpha} emission from moderate-resolution (~2600), red spectroscopy of 434 faint candidate members and 126 field control stars demonstrates that ~60%-80% of candidates within 2{deg} of the cluster center are genuine Praesepe members.
- ID:
- ivo://CDS.VizieR/J/AJ/124/1001
- Title:
- JHKs photometry of Cha I variables
- Short Name:
- J/AJ/124/1001
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a J, H, and Ks photometric monitoring campaign of a 0.72{deg}x6{deg} area centered on the Chamaeleon I star-forming region. Data were obtained on 15 separate nights over a 4 month time interval, from January to May 2000, using the Two Micron All Sky Survey south telescope. Out of a total of 34,539 sources brighter than the photometric completeness limits (J=16.0, H=15.2, and Ks=14.8), 95 exhibit near-infrared variability in one or more bands. The variables can be grouped into a population of bright, red objects that are associated with the Chamaeleon I association and a population of faint, blue variables that are dispersed over the full 6{deg} of the survey and are likely field stars or older pre-main-sequence stars unrelated to the present-day Chamaeleon I molecular cloud. Ten new candidate members of Chamaeleon I, including eight brown dwarf candidates, have been identified based on variability and/or near-infrared-excess emission in the J-H versus H-Ks color-color diagram. We also provide a compendium of astrometry and J, H, and Ks photometry for previously identified members and candidate members of Chamaeleon I.
- ID:
- ivo://CDS.VizieR/J/A+A/462/599
- Title:
- JHKs photometry of LMC cluster Cepheids
- Short Name:
- J/A+A/462/599
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This work presents IR photometry for two young clusters known to contain sizeable Cepheid populations: NGC 1866 and NGC 2031. The goal is to determine light curves and period-luminosity (PL) relations in the near-IR, to assess the similarity between cluster and field pulsators, and to examine the predictive capability of current pulsation models. The light curves are obtained from multiwavelength broadband J,H,Ks photometry of Cepheids in both clusters, with periods previously established from optical photometry. Mean magnitudes for the Cepheids are used to construct period-luminosity (PL) relations in the near-IR. The properties in the PL planes are compared with the behavior of field Cepheids in the LMC and with the predictions of recent pulsational models, both canonical and overluminous. Cluster and field Cepheids are homogeneous and the inclusion of the cluster Cepheids in the field sample extends the PL relation. The slope of the PL relation is constant over the whole period range and does not show, at least in the adopted IR bands, the break in slope at P~10d reported by some authors. A comparison with the predictions of pulsation models allows an estimate for the distance moduli of NGC 1866 and NGC 2031. The two clusters are found to lie at essentially the same distance. Fitting of theoretical models to the data gives, for the K filter, (m-M)_0_=18.62+/-0.10 if canonical models are used and (m-M)_0_=18.42+/-0.10 if overluminous models are used.
- ID:
- ivo://CDS.VizieR/J/other/BASI/35.53
- Title:
- JH photometry of Berkeley 59
- Short Name:
- J/other/BASI/35.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared JH photometry and optical slitless spectroscopy of stars in the field of the young cluster Be 59. The J/(J-H) colour-magnitude diagram of the cluster yields a distance modulus of (m-M)_0_=10.0+/-0.2mag, which corresponds to a distance of 1.0+/-0.1kpc. Using the slitless spectroscopy we identified 9 H{alpha} emission line stars in the observed region. The location of H{alpha} stars in the CMD indicates that they may be pre-main sequence stars. We have estimated the age of the cluster using the turn-off and turn-on points and is found to lie between ~1Myr to 4Myr. Two massive stars (~25M_{sun}_) in the cluster region have high membership probability which indicates that the low mass stars (~0.8M_{sun}_) may co-exist with massive stars.
- ID:
- ivo://CDS.VizieR/J/A+A/372/879
- Title:
- JKBV photometry of NGC 2141
- Short Name:
- J/A+A/372/879
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report CCD optical (B and V passbands) and near IR (J and K bands) observations in the region of the old open cluster NGC 2141. By combining the two sets of photometry (500 stars in common) we derive new estimates of the cluster's fundamental parameters. We confirm that the cluster is 2.5Gyrs old, but, with respect to previous investigations, we obtain a slightly larger reddening (E(B-V)=0.40), and a slightly shorter distance (3.8kpc) from the Sun. Finally, we present the Luminosity Function (LF) in the V band, which is another age indicator. We provide a good fit for the age range inferred from isochrones by assuming the Kroupa et al. (1993MNRAS.262..545K) IMF up to M_V_=5.0. We interpret the disagreement at fainter magnitudes as evidence of mass segregation.
- ID:
- ivo://CDS.VizieR/J/A+A/420/173
- Title:
- JK photometry of Omega Cen red giants
- Short Name:
- J/A+A/420/173
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The IR catalogue of omega Cen is based on ground-based observations using SOFI (Infrared Spectrograph and Imaging Camera on the NTT telescope at ESO, La Silla) and contains about 73000 stars covering an area of 13"x13" around the center of the cluster. The limiting magnitude is K<=17.5m and the positional accuracy is better than 0.2"
- ID:
- ivo://CDS.VizieR/J/A+A/409/147
- Title:
- J magnitude of IC 348 brown dwarfs
- Short Name:
- J/A+A/409/147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use a deep near-infrared census of the young stellar cluster IC 348 to construct and analyze its luminosity function. Our mosaic image of IC 348 covers the full extent of the cluster with a completeness limit of J~19.5 and is therefore sensitive for 2Myr old cluster members with masses as low as M>=0.005M_{sun}_ or the mean extinction of the known cluster members (A_V_~3.5mag).