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4301. 90 new SNIa from SDSS DR7
ID:
ivo://CDS.VizieR/J/MNRAS/430/1746
Title:
90 new SNIa from SDSS DR7
Short Name:
J/MNRAS/430/1746
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using a method to discover and classify supernovae (SNe) in galaxy spectra, we find 90 Type Ia SNe (SNe Ia) and 10 Type II SNe among the ~700000 galaxy spectra in the Sloan Digital Sky Survey Data Release 7 that have star-formation histories (SFHs) derived with the VErsatile SPectral Analysis code (VESPA). We use the SN Ia sample to measure SN Ia rates per unit stellar mass.
4302. New SpeX Observations of M7-L6 Dwarfs
ID:
ivo://CDS.VizieR/J/ApJ/794/143
Title:
New SpeX Observations of M7-L6 Dwarfs
Short Name:
J/ApJ/794/143
Date:
21 Oct 2021
Publisher:
CDS
Description:
Multiplicity is a key statistic for understanding the formation of very low mass (VLM) stars and brown dwarfs. Currently, the separation distribution of VLM binaries remains poorly constrained at small separations (<=1 AU), leading to uncertainty in the overall binary fraction. We approach this problem by searching for late-M/early-L plus T dwarf spectral binaries whose combined light spectra exhibit distinct peculiarities, allowing for separation-independent identification. We define a set of spectral indices designed to identify these systems, and we use a spectral template fitting method to confirm and characterize spectral binary candidates from a library of 815 spectra from the SpeX Prism Spectral Libraries. We present 11 new binary candidates, confirm 3 previously reported candidates, and rule out 2 previously identified candidates, all with primary and secondary spectral types in the range M7-L7 and T1-T8, respectively. We find that subdwarfs and blue L dwarfs are the primary contaminants in our sample and propose a method for segregating these sources. If confirmed by follow-up observations, these systems may add to the growing list of tight separation binaries, whose orbital properties may yield further insight into brown dwarf formation scenarios.
4303. New stellar members of Coma Berenices cluster
ID:
ivo://CDS.VizieR/J/MNRAS/365/447
Title:
New stellar members of Coma Berenices cluster
Short Name:
J/MNRAS/365/447
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a survey of the Coma Berenices open star cluster (Melotte 111), undertaken using proper motions from the USNO-B1.0 (United States Naval Observatory, <I/284>) and photometry from the Two-Micron All-Sky Survey (2MASS, <II/246>) Point Source catalogues. We have identified 60 new candidate members with masses in the range 1.007<M<0.269M_{sun}_. For each we have estimated a membership probability by extracting control clusters from the proper motion vector diagram. All 60 are found to have greater than 60 per cent probability of being members, more than doubling the number of known cluster members. The new luminosity function for the cluster peaks at bright magnitudes, but is rising at K>>12, indicating that it is likely that lower mass members may exist. The mass function also supports this hypothesis.
4304. New substellar discoveries from Kepler and K2
ID:
ivo://CDS.VizieR/J/AJ/158/38
Title:
New substellar discoveries from Kepler and K2
Short Name:
J/AJ/158/38
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the discoveries of a brown dwarf (BD) and a low-mass star from the Kepler and K2 missions. The newly discovered BD is EPIC 212036875b and the low-mass star is KOI-607b. EPIC 212036875b has a mass of M_b_=52.3+/-1.9 M_J_, a radius of R_b_=0.874+/-0.017 R_J_, and orbits its host star in P=5.169885+/-0.000027 days. Its host star is a late F-type star with M_*_=1.288+/-0.065 M_{sun}_, R_*_= 1.498+/-0.025 R_{sun}_, and T_eff_=6238+/-60 K. KOI-607b has a mass of M_b_=95.1+/-3.4 M_J_, a radius of R_b_=1.089+/-0.089 R_J_, and an orbital period of P=5.89399148+/-0.00000060 days. The primary star in the KOI-607 system is a G dwarf with M_*_=0.993+/-0.052 M_{sun}_, R_*_= 0.915+/-0.031 R_{sun}_, and T_eff_=5418+/-87 K. We also revisit a BD, CWW 89Ab, that was previously published by Nowak et al. 2017AJ....153..131N (under the designation EPIC 219388192b). CWW 89Ab is one of two known transiting BDs associated with a star cluster, which illustrates the need for more BDs with accurate masses, radii, and reliable age determinations to test theoretical models. We find that the newly discovered BD, EPIC 212036875b, falls in the middle of the so-called BD desert, indicating that EPIC 212036875b is either a particularly rare object, or the BD desert may not be so dry after all.
4305. New survey of supergiants in the MCs
ID:
ivo://CDS.VizieR/J/A+A/578/A3
Title:
New survey of supergiants in the MCs
Short Name:
J/A+A/578/A3
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this study, we conduct a pilot program aimed at the red supergiant population of the Magellanic Clouds. We intend to extend the current known sample to the unexplored low end of the brightness distribution of these stars, building a more representative dataset with which to extrapolate their behaviour to other Galactic and extra-galactic environments. We select candidates using only near infrared photometry, and with medium resolution multi-object spectroscopy, we perform spectral classification and derive their line-of-sight velocities, confirming the nature of the candidates and their membership to the clouds. Around two hundred new RSGs have been detected, hinting at a yet to be observed large population. Using near and mid infrared photometry we study the brightness distribution of these stars, the onset of mass-loss and the effect of dust in their atmospheres. Based on this sample, new a priori classification criteria are investigated, combining mid and near infrared photometry to improve the observational efficiency of similar programs as this.
4306. New Taurus members from stellar to planetary masses
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.
4307. New T dwarfs identified in Pan-STARRS 1
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.
4308. 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.
4309. New times of maximum of CY Aqr
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).
4310. 10 new transit light curves of HAT-P-13b
ID:
ivo://CDS.VizieR/J/AJ/142/84
Title:
10 new transit light curves of HAT-P-13b
Short Name:
J/AJ/142/84
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 10 new transit light curves of the transiting hot Jupiter HAT-P-13b, obtained during two observational seasons by three different telescopes. When combined with 12 previously published light curves, we have a sample consisting of 22 transit light curves, spanning 1041 days across four observational seasons. We use this sample to examine the recently observed large-amplitude transit timing variations (TTVs) by Pal et al. (2011MNRAS.413L..43P) and give refined system parameters. We find that the transit times are consistent with a linear ephemeris, with the exception of a single transit time, from UT 2009 November 5, for which the measured mid-transit time significantly deviates from our linear ephemeris. The nature of this deviation is not clear, and the rest of the data do not show any significant TTVs.