- ID:
- ivo://CDS.VizieR/J/AJ/158/54
- Title:
- New Taurus members from stellar to planetary masses
- Short Name:
- J/AJ/158/54
- Date:
- 06 Dec 2021 11:31:43
- Publisher:
- CDS
- Description:
- We present a large sample of new members of the Taurus star-forming region that extend from stellar to planetary masses. To identify candidate members at substellar masses, we have used color-magnitude diagrams and proper motions measured with several wide-field optical and infrared (IR) surveys. At stellar masses, we have considered the candidate members that were found in a recent analysis of high-precision astrometry from the Gaia mission. Using new and archival spectra, we have measured spectral types and assessed membership for these 161 candidates, 79 of which are classified as new members. Our updated census of Taurus now contains 519 known members. According to Gaia data, this census should be nearly complete for spectral types earlier than M6-M7 at A_J_<1. For a large field encompassing ~72% of the known members, the census should be complete for K<15.7 at A_J_<1.5, which corresponds to ~5-13 M_Jup_ for ages of 1-10 Myr based on theoretical evolutionary models. Our survey has doubled the number of known members at >=M9 and has uncovered the faintest known member in M_K_, which should have a mass of ~3-10 M_Jup_ for ages of 1-10 Myr. We have used mid-IR photometry from the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer to determine whether the new members exhibit excess emission that would indicate the presence of circumstellar disks. The updated disk fraction for Taurus is ~0.7 at =<M3.5 and ~0.4 at >M3.5.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/142/77
- Title:
- New T dwarfs identified in Pan-STARRS 1
- Short Name:
- J/AJ/142/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A complete well-defined sample of ultracool dwarfs is one of the key science programs of the Pan-STARRS 1 optical survey telescope (PS1). Here we combine PS1 commissioning data with the Two Micron All Sky Survey (2MASS) to conduct a proper motion search (0.1-2.0"/yr) for nearby T dwarfs, using optical+near-IR colors to select objects for spectroscopic follow-up. The addition of sensitive far-red optical imaging from PS1 enables discovery of nearby ultracool dwarfs that cannot be identified from 2MASS data alone. We have searched 3700deg^2^ of PS1 y-band (0.95-1.03um) data to y~19.5mag (AB) and J~16.5mag (Vega) and discovered four previously unknown bright T dwarfs. Three of the objects (with spectral types T1.5, T2, and T3.5) have photometric distances within 25pc and were missed by previous 2MASS searches due to more restrictive color selection criteria. The fourth object (spectral type T4.5) is more distant than 25pc and is only a single-band detection in 2MASS. We also examine the potential for completing the census of nearby ultracool objects with the PS1 3{PI} survey.
1963. 11 new T dwarfs in 2MASS
- ID:
- ivo://CDS.VizieR/J/AJ/134/1162
- Title:
- 11 new T dwarfs in 2MASS
- Short Name:
- J/AJ/134/1162
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of 11 new T dwarfs, found during the course of a photometric survey for mid-to-late T dwarfs in the 2MASS Point Source Catalog and from a proper-motion-selected sample of ultracool dwarfs in the 2MASS Working Database. Using the NASA Infrared Telescope Facility SpeX spectrograph, we obtained low-resolution (R~150) spectroscopy, allowing us to derive near-infrared spectral types of T2-T8. We also present improved signal-to-noise ratio SpeX low-resolution spectroscopy of the near-infrared T0 standard SDSS J120747.17+024424.8 and T1 standard SDSSp J083717.22-000018.3. One of these new T dwarfs, 2MASS J13243559+6358284, was also discovered independently by Metchev et al.
- ID:
- ivo://CDS.VizieR/J/other/JAD/16.2
- Title:
- New times of maximum of CY Aqr
- Short Name:
- J/other/JAD/16.2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a collection of 102 new times of maximum of the SX Phoenicis star CY Aquarii. These times, together with 20 times of maximum taken from the literature, lead to a new local linear ephemeris for 2003-2009 with a formally slightly shorter period than the one for 1996-2002. It will require at least another half decade of additional monitoring before any significant update to any model can be considered. Such monitoring should preferably occur at regular intervals, be done in a consistent photometric band, and at high time resolution. A set of 114 new times of maximum obtained since 2002 leads to a new local linear ephemeris for 2003-2009: Tmax=2426159.512(+/-0.001)+0.061038349E(+/-0.000000002).
- ID:
- ivo://CDS.VizieR/J/A+A/539/A28
- Title:
- New transit photometry for super-Earth 55 Cnc e
- Short Name:
- J/A+A/539/A28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on new transit photometry for the super-Earth 55 Cnc e obtained with Warm Spitzer/IRAC at 4.5um. An individual analysis of these new data leads to a planet radius of 2.21^+0.15^_-0.16_R_{earth}_, in good agreement with the values previously derived from the MOST and Spitzer transit discovery data. A global analysis of both Spitzer transit time-series improves the precision on the radius of the planet at 4.5um to 2.20+/-0.12R_{earth}_. We also performed an independent analysis of the MOST data, paying particular attention to the influence of the systematic effects of instrumental origin on the derived parameters and errors by including them in a global model instead of performing a preliminary detrending-filtering processing. We deduce from this reanalysis of MOST data an optical planet radius of 2.04+/-0.15R_{earth}_ that is consistent with our Spitzer infrared radius
- ID:
- ivo://CDS.VizieR/J/A+A/383/30
- Title:
- New UBVRI color distribution in E galaxies
- Short Name:
- J/A+A/383/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Colour distributions have been obtained for 36 E and 4 SA0 galaxies of the northern Local Supercluster, observed in 2000/2001 at the 120cm telescope of Observatoire de Haute-Provence: field 11.6'x11.6'; scale 0.68"/pix. The radial profiles of the V magnitude and the colours U-B, B-V, V-R and V-I, were measured in greatly enlarged radial ranges, as compared to previous work, and with an improved accuracy. The colour system is the one of Cousins.
- ID:
- ivo://CDS.VizieR/J/A+A/497/619
- Title:
- New ultra-cool dwarfs from SDSS and 2MASS
- Short Name:
- J/A+A/497/619
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We try to identify ultra-cool dwarfs from the seventh Data Release of the Sloan Digital Sky Survey (SDSS DR7) with SDSS i-z and r-z colors. We also obtain proper motion data from SDSS, 2MASS, and UKIDSS and improve spectral typing from SDSS and 2MASS photometric colors.
1968. New ultracool subdwarfs
- ID:
- ivo://CDS.VizieR/J/A+A/598/A92
- Title:
- New ultracool subdwarfs
- Short Name:
- J/A+A/598/A92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We developed an efficient method to search for late-type subdwarfs. We carried out a search cross-matching SDSS, 2MASS, and UKIDSS with VO tools. We considered different photometric and proper motion criteria for our selection. We identified 100 late-type subdwarf candidates. We obtained our own low-resolution optical spectra for 71 of our candidates and retrieved Sloan spectra for 30 of them (9 in common to the 71). We classified 92 candidates based on optical spectra. Our new discoveries include 49 subdwarfs, 25 extreme subdwarfs, six ultrasubdwarfs, one subdwarf/extreme subdwarf, and two dwarfs/subdwarfs. In addition, we discovered three early-L subdwarfs. We double the numbers of cool subdwarfs and derived a surface density of late-type subdwarfs.
- ID:
- ivo://CDS.VizieR/J/other/NewA/49.50
- Title:
- New Variables in 3 Galactic open clusters
- Short Name:
- J/other/NewA/49.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This project is a massive near-infrared (NIR) search for variable stars in highly reddened and obscured open cluster (OC) fields projected on regions of the Galactic bulge and disk. The search is performed using photometric NIR data in the J-, H- and Ks - bands obtained from the Vista Variables in the Via Lactea (VVV) Survey. We performed in each cluster field a variability search using Stetson's variability statistics to select the variable candidates. Later, those candidates were subjected to a frequency analysis using the Generalized Lomb-Scargle and the Phase Dispersion Minimization algorithms. The number of independent observations range between 63 and 73. The newly discovered variables in this study, 157 in total in three different known OCs, are classified based on their light curve shapes, periods, amplitudes and their location in the corresponding color-magnitude (J-Ks,Ks)(J-Ks,Ks) and color-color (H-Ks,J-H)(H-Ks,J-H) diagrams. We found 5 possible Cepheid stars which, based on the period-luminosity relation, are very likely type II Cepheids located behind the bulge. Among the newly discovered variables, there are eclipsing binaries, {delta} Scuti, as well as background RR Lyrae stars. Using the new version of the Wilson & Devinney code as well as the "Physics Of Eclipsing Binaries" (PHOEBE) code, we analyzed some of the best eclipsing binaries we discovered. Our results show that these studied systems turn out to be ranging from detached to double-contact binaries, with low eccentricities and high inclinations of approximately 80{deg}. Their surface temperatures range between 3500K and 8000K.
1970. New variables in ONC
- ID:
- ivo://CDS.VizieR/J/MNRAS/400/603
- Title:
- New variables in ONC
- Short Name:
- J/MNRAS/400/603
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since 2004, we have been engaged in a long-term observing programme to monitor young stellar objects (YSOs) in the Orion Nebula Cluster (ONC). We have collected about 2000 frames in V, R and I broad-band filters on more than 200 nights distributed over five consecutive observing seasons. The high-quality and time-extended photometric data give us an opportunity to address various phenomena associated with young stars.
