- ID:
- ivo://CDS.VizieR/J/A+AS/122/483
- Title:
- Terzan 6 NTT VI photometry
- Short Name:
- J/A+AS/122/483
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present for the first time optical (V, I and Gunn z) colour magnitude diagrams for Terzan 6, which were collected under excellent seeing conditions with the ESO NTT telescope. The horizontal branch morphology is red, nearly superimposed on the red giant branch. The red giant branch morphology presents characteristics intermediate between those of 47 Tuc and NGC 6528/NGC 6553. We derive a reddening of E(B-V)=2.24 and a distance d_{sun}_=7.0kpc (assuming R=3.1). We conclude that Terzan 6 belongs to the metal-rich bulge globular cluster system.
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6622. Terzan 2 VI photometry
- ID:
- ivo://CDS.VizieR/J/A+A/326/614
- Title:
- Terzan 2 VI photometry
- Short Name:
- J/A+A/326/614
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present for the first time optical colour magnitude diagrams of the globular cluster Terzan 2, in the V, I colours. The horizontal branch is red. The red giant branch morphology can be fitted with that of 47 Tuc, but definitely not th at of NGC 6553. We derive a reddening of E(B-V)=1.54 and a distance d_{sun}_=7.7kpc if R=3.1, or 5.3kpc if R=3.6. Terzan 2 adds to the list of bulge metal-rich clusters now with reliable parameters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/473/2004
- Title:
- TESS-HERMES Survey Data Release 1 catalog
- Short Name:
- J/MNRAS/473/2004
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Transiting Exoplanet Survey Satellite (TESS) will provide high-precision time series photometry for millions of stars with at least a half-hour cadence. Of particular interest are the circular regions of 12{deg} radius centred around the ecliptic poles that will be observed continuously for a full year. Spectroscopic stellar parameters are desirable to characterize and select suitable targets for TESS, whether they are focused on exploring exoplanets, stellar astrophysics or Galactic archaeology. Here, we present spectroscopic stellar parameters (Teff, logg, [Fe/H], vsini, vmicro) for about 16000 dwarf and subgiant stars in TESS' southern continuous viewing zone. For almost all the stars, we also present Bayesian estimates of stellar properties including distance, extinction, mass, radius and age using theoretical isochrones. Stellar surface gravity and radius are made available for an additional set of roughly 8500 red giants. All our target stars are in the range 10<V<13.1. Among them, we identify and list 227 stars belonging to the Large Magellanic Cloud. The data were taken using the High Efficiency and Resolution Multi-Element Spectrograph (HERMES; R~28000) at the Anglo-Australian Telescope as part of the TESS-HERMES survey. Comparing our results with the TESS Input Catalogue (TIC) shows that the TIC is generally efficient in separating dwarfs and giants, but it has flagged more than 100 cool dwarfs (Teff<4800K) as giants, which ought to be high-priority targets for the exoplanet search. The catalogue can be accessed via http://www.physics.usyd.edu.au/tess-hermes/, or at Mikulski Archive for Space Telescopes (MAST).
- ID:
- ivo://CDS.VizieR/IV/39
- Title:
- TESS Input Catalog version 8.2 (TIC v8.2)
- Short Name:
- IV/39
- Date:
- 03 Mar 2022 07:19:26
- Publisher:
- CDS
- Description:
- We define various types of "phantom" stars that may appear in the TESS Input Catalog (TIC), and provide examples and lists of currently known cases. We present a methodology that can be used to check for phantoms around any object of interest in the TIC, and we present an approach for correcting the TIC-reported flux contamination factors accordingly. We checked all 2077 TESS Objects of Interest (TOIs) known as of July 21st 2020 (Sectors 1 to 24) and sent corrections for 291 stars to MAST where they are integrated into the publicly available TIC-8, updating it to TIC 8.1. We used the experience gained to construct an all-sky algorithm searching for "phantoms" which led to 34 million updates integrated into TIC 8.2.
- ID:
- ivo://CDS.VizieR/IV/38
- Title:
- TESS Input Catalog - v8.0 (TIC-8)
- Short Name:
- IV/38
- Date:
- 11 Feb 2022 14:26:27
- Publisher:
- CDS
- Description:
- The TIC is used to help identify two-minute cadence target selection for the Transiting Exoplanet Survey Satellite (TESS) mission, and to calculate physical and observational properties of planet candidates. It is for use by both the TESS science team and the public, and it is periodically updated - the current version is TIC-8. TIC-8 uses the GAIA DR2 catalog as a base and merges a large number of other photometric catalogs, including 2MASS, UCAC4, APASS, SDSS, WISE, etc. There are roughly 1.5 billion stellar and extended sources in TIC-8, containing compiled magnitudes including B, V, u, g, r, i, z, J, H, K, W1-W4, and G. This version was released in May 2019, and is expected to be the last official version of the TIC produced by the TESS mission, although future, independent development of the TIC is possible. The TIC is the responsibility of the SAO Arm of the TESS Science Office under the leadership of David Latham. The TESS Target Selection Working Group (TSWG) is co-chaired by Keivan Stassun (Vanderbilt) & Joshua Pepper (Lehigh).
- ID:
- ivo://CDS.VizieR/J/ApJ/899/136
- Title:
- TESS light curve of AGN NGC 4395
- Short Name:
- J/ApJ/899/136
- Date:
- 03 Dec 2021 13:06:51
- Publisher:
- CDS
- Description:
- We present optical light curves from the Transiting Exoplanet Survey Satellite (TESS) for the archetypical dwarf active galactic nucleus (AGN) in the nearby galaxy NGC 4395 hosting a ~105M{sun} supermassive black hole (SMBH). Significant variability is detected on timescales from weeks to hours before reaching the background noise level. The ~month-long, 30 minute-cadence, high-precision TESS light curve can be well fit by a simple damped random walk (DRW) model, with the damping timescale {tau}DRW constrained to be 2.3_-0.7_^+1.8^days (1{sigma}). NGC 4395 lies almost exactly on the extrapolation of the {tau }_DRW_-M_BH_ relation measured for AGNs with BH masses that are more than three orders of magnitude larger. The optical variability periodogram can be well fit by a broken power law with the high-frequency slope (-1.88{+/-}0.15) and the characteristic timescale ({tau}_br_=1/(2{pi}f_br_)=1.4_-0.5_^+1.9^days) consistent with the DRW model within 1{sigma}. This work demonstrates the power of TESS light curves in identifying low-mass accreting SMBHs with optical variability, and a potential global {tau}_DRW}_-M_BH_ relation that can be used to estimate SMBH masses with optical variability measurements.
- ID:
- ivo://CDS.VizieR/J/A+A/625/L13
- Title:
- TESS light curve of beta Pictoris
- Short Name:
- J/A+A/625/L13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We search for signs of falling evaporating bodies (FEBs, also known as exocomets) in photometric time series obtained for {beta} Pictoris after fitting and removing its {delta} Scuti-type pulsation frequencies. Using photometric data obtained by the TESS satellite we determined the pulsational properties of the exoplanet host star {beta} Pictoris through frequency analysis. We then pre-whitened the 54 identified {delta} Scuti p-modes and investigated the residual photometric time series for the presence of FEBs. We identify three distinct dipping events in the light curve of {beta} Pictoris over a 105-day period. These dips have depths from 0.5 to 2-millimagnitudes and durations of up to 2-days for the largest dip. These dips are asymmetric in nature and are consistent with a model of an evaporating comet with an extended tail crossing the disc of the star. We present the first broadband detections of exocomets crossing the disc of {beta} Pictoris, complementing the predictions made 20 years earlier by Lecavelier Des Etangs et al. (1999A&A...343..916L). No periodic transits are seen in this time series. These observations confirm the spectroscopic detection of exocomets in calcium H and K lines that have been seen in high resolution spectroscopy.
- ID:
- ivo://CDS.VizieR/J/AJ/158/45
- Title:
- TESS light curve & radial velocities for HD 1397
- Short Name:
- J/AJ/158/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a transiting planet first identified as a candidate in Sector 1 of the Transiting Exoplanet Survey Satellite (TESS), and then confirmed with precision radial velocities. HD 1397b has a mass of M_P_=0.367_-0.023_^+0.022^ M_J_, a radius of R_P_=1.023_-0.013_^+0.013^ R_J_, and orbits its bright host star (V=7.8 mag) with an orbital period of 11.5366+/-0.0003 d on a moderately eccentric orbit (e=0.216_-0.026_^+0.027^). With a mass of M_*_=1.257_-0.029_^+0.029^ M_{sun}_, a radius of R_*_=2.341_-0.019_^+0.022^ R_{sun}_, and an age of 4.46+/-0.25 Gyr, the solar-metallicity host star has already departed from the main sequence. We find evidence in the radial velocity measurements of a secondary signal with a longer period. We attribute it to the rotational modulation of stellar activity, but a long-term radial velocity monitoring would be necessary to discard if this signal is produced by a second planet in the system. The HD 1397 system is among the brightest ones currently known to host a transiting planet, which will make it possible to perform detailed follow-up observations in order to characterize the properties of giant planets orbiting evolved stars.
- ID:
- ivo://CDS.VizieR/J/A+A/630/A114
- Title:
- TESS light curves detection limits
- Short Name:
- J/A+A/630/A114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The primary targets of the NASA Transiting Exoplanet Survey Satellite will be K and M dwarf stars within our solar neighbourhood. Young K and M dwarf stars are known to exhibit a high starspot coverage (~50%), however, older stars are known to show fewer starspots. This implies that TESS 2 min cadence transit light curves may contain starspot anomalies, and if so, will require transit-starspot models to accurately determine the properties of the system. The goals are to determine if starspot anomalies can manifest in TESS transit light curves, to determine the detection limits of the starspot anomalies and to examine the relationship between the change in flux caused by the starspot anomaly and the planetary transit. 20573 simulations of planetary transits around spotted stars were conducted using the transit-starspot model, PRISM. In total 3888 different scenarios were considered using three different host star spectral types, M4V, M1V and K5V. The mean amplitude of the starspot anomaly was measured and compared to the photometric precision of the light curve, to determine if the starspot anomaly's characteristic "blip" was noticeable in the light curve. Results. The simulations show that, starspot anomalies will be observable in TESS 2 min cadence data. The smallest starspot detectable in TESS transit light curves has a radius of ~1900km. The starspot detection limits for the three host stars are: 4900+/-1700km (M4V), 13800+/-6000km (M1V) and 15900+/-6800km (K5V). The smallest change in flux of the starspot ({Delta}F_spot_=0.00015+/-0.00001) can be detected when the ratio between the planetary and stellar radii, k=0.082+/-0.004. The results confirm known dependencies between the amplitude of the starspot anomaly and the photometric parameters of the light curve. The results allowed the characterisation of the relationship between the change in flux of the starspot anomaly and the change in flux of the planetary transit for TESS transit light curves.
- ID:
- ivo://CDS.VizieR/J/ApJS/253/11
- Title:
- TESS observations of Cepheid stars
- Short Name:
- J/ApJS/253/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first analysis of Cepheid stars observed by the TESS space mission in Sectors 1-5. Our sample consists of 25 pulsators: ten fundamental mode, three overtone and two double-mode classical Cepheids, plus three type II and seven anomalous Cepheids. The targets were chosen from fields with different stellar densities, both from the Galactic field and from the Magellanic System. Three targets have 2 minutes cadence light curves available by the TESS Science Processing Operations Center: for the rest, we prepared custom light curves from the full-frame images with our own differential photometric FITSH pipeline. Our main goal was to explore the potential and the limitations of TESS concerning the various subtypes of Cepheids. We detected many low-amplitude features: weak modulation, period jitter, and timing variations due to light-time effect. We also report signs of nonradial modes and the first discovery of such a mode in an anomalous Cepheid, the overtone star XZ Cet, which we then confirmed with ground-based multicolor photometric measurements. We prepared a custom photometric solution to minimize saturation effects in the bright fundamental-mode classical Cepheid, {beta} Dor with the lightkurve software, and we revealed strong evidence of cycle-to-cycle variations in the star. In several cases, however, fluctuations in the pulsation could not be distinguished from instrumental effects, such as contamination from nearby sources, which also varies between sectors.