The Magellan-TESS Survey I: Survey Description and Mid-Survey Results
Johanna Teske, Sharon Xuesong Wang, Angie Wolfgang, Tianjun Gan, Mykhaylo Plotnykov, David J. Armstrong, R. Paul Butler, Bryson Cale, Jeffrey D. Crane, Ward How… 展开作者
Johanna Teske, Sharon Xuesong Wang, Angie Wolfgang, Tianjun Gan, Mykhaylo Plotnykov, David J. Armstrong, R. Paul Butler, Bryson Cale, Jeffrey D. Crane, Ward Howard, Eric L. N. Jensen, Nicholas Law, Stephen A. Shectman, Peter Plavchan, Diana Valencia, Andrew Vanderburg, George Ricker, Roland Vanderspek, Dave W. Latham, Sara Seager, Joshua W. Winn, Jon M. Jenkins, Vardan Adibekyan, David Barrado, Susana C. C. Barros, Zouhair Benkhaldoun, David J. A. Brown, Edward M. Bryant, Jennifer Burt, Douglas A. Caldwell, David Charbonneau, Ryan Cloutier, Karen A. Collins, Kevin I. Collins, Nicole D. Colon, Dennis M. Conti, Olivier D. S. Demangeon, Jason D. Eastman, Mohammed Elmufti, Fabo Feng, Erin Flowers, Natalia M. Guerrero, Saeed Hojjatpanah, Jonathan M. Irwin, Giovanni Isopi, Jorge Lillo-Box, Franco Mallia, Bob Massey, Mayuko Mori, Susan E. Mullally, Norio Narita, Taku Nishiumi, Ares Osborn, Martin Paegert, Jerome Pitogo de Leon, Samuel N. Quinn, Michael Reefe, Richard P. Schwarz, Avi Shporer, Abderahmane Soubkiou, Sérgio G. Sousa, Chris Stockdale, Paul A. Strøm, Thiam-Guan Tan, Peter Tenenbaum, Peter J. Wheatley, Justin Wittrock, Daniel A. Yahalomi, Farzaneh Zohrabi
备注：
Minor updates to some masses, and new exploration of broken power law M-R relation. 66 pages (now some figures moved to figure sets, will be in HTML published version). Accepted to ApJS on June 22, 2021
$Kepler$ revealed that roughly one-third of Sun-like stars host planets orbiting within 100 days and between the size of Earth and Neptune. How do these planets form, what are they made of, and do they represent a continuous population or multiple populations? To help address these questions, we began the Magellan-TESS Survey (MTS), which uses Magellan II/PFS to obtain radial velocity (RV) masses of 30 TESS-detected exoplanets and develops an analysis framework that connects observed planet distributions to underlying populations. In the past, small planet RV measurements have been challenging to obtain due to host star faintness and low RV semi-amplitudes, and challenging to interpret due to the potential biases in target selection and observation planning decisions. The MTS attempts to minimize these biases by focusing on bright TESS targets and employing a quantitative selection function and observing strategy. In this paper, we (1) describe our motivation and survey strategy, (2) present our first catalog of planet density constraints for 27 TESS Objects of Interest (TOIs; 22 in our population analysis sample, 12 that are members of the same systems), and (3) employ a hierarchical Bayesian model to produce preliminary constraints on the mass-radius (M-R) relation. We find that the biases causing previous M-R relations to predict fairly high masses at $1~R_\oplus$ have been reduced. This work can inform more detailed studies of individual systems and offer a framework that can be applied to future RV surveys with the goal of population inferences.
Stellar RV jitter due to surface activity may bias the RV semi-amplitude and mass of rocky planets. The amplitude of the jitter may be estimated from the uncertainty in the rotation period, allowing the mass to be more accurately obtained. We find candidate rotation periods for 17 out of 35 TESS Objects of Interest (TOI) hosting <3 R_Earth planets as part of the Magellan-TESS Survey, which is the first-ever statistically robust study of exoplanet masses and radii across the photo-evaporation gap. Seven periods are 3+ sigma detections, two are 1.5+ sigma, and 8 show plausible variability but th…
We report the detection of a transiting, dense Neptune planet candidate orbiting the bright ($V=8.6$) K0.5V star HD 95338. Detection of the 55-day periodic signal comes from the analysis of precision radial velocities from the Planet Finder Spectrograph on the Magellan II Telescope. Follow-up observations with HARPS also confirm the presence of the periodic signal in the combined data. HD 95338 was also observed by the Transiting Exoplanet Survey Satellite ({\it TESS}) where we identify a clear single transit in the photometry. A Markov Chain Monte Carlo period search on the velocities allows …
We present the discovery of TOI-2136b, a sub-Neptune planet transiting every 7.85 days a nearby M4.5V-type star, identified through photometric measurements from the TESS mission. The host star is located $33$ pc away with a radius of $R_{\ast} = 0.34\pm0.02\ R_{\odot}$, a mass of $0.34\pm0.02\ M_{\odot}$ and an effective temperature of $\rm 3342\pm100\ K$. We estimate its stellar rotation period to be $75\pm5$ days based on archival long-term photometry. We confirm and characterize the planet based on a series of ground-based multi-wavelength photometry, high-angular-resolution imaging observ…
In this paper we investigate systems previously identified to exhibit transit timing variations (TTVs) in Kepler data, with the goal of predicting the expected improvements to the mass and eccentricity constraints that will arise from combining Kepler data with future data from the TESS mission. We advocate for the use of the Kullback-Leibler (KL) divergence as a means to quantify improvements in the measured constraints. Compared to the original Kepler data, the TESS data will have a lower signal-to-noise ratio, rendering some of the planetary transits undetectable, and lowering the accuracy …
Much of the science from the exoplanets detected by the TESS mission relies on precisely predicted transit times that are needed for many follow-up characterization studies. We investigate ephemeris deterioration for simulated TESS planets and find that the ephemerides of 81% of those will have expired (i.e. 1$σ$ mid-transit time uncertainties greater than 30 minutes) one year after their TESS observations. We verify these results using a sample of TESS planet candidates as well. In particular, of the simulated planets that would be recommended as JWST targets by Kempton et al. (2018), $\sim$8…
The Transiting Exoplanet Survey Satellite (TESS) is NASA's latest space telescope dedicated to the discovery of transiting exoplanets around nearby stars. Besides the main goal of the mission, asteroseismology is an important secondary goal and very relevant for the high-quality time series that TESS will make during its two year all-sky survey. Using TESS for asteroseismology introduces strong timing requirements, especially for coherent oscillators. Although the internal clock on board TESS is precise in its own time, it might have a constant drift and will thus need calibration, or offsets …
Recent discoveries have demonstrated that planetary systems routinely survive the post-main sequence evolution of their host stars, leaving the resulting white dwarf with a rich circumsteller environment. Among the most intriguing of such hosts is the hot white dwarf GD 394, exhibiting a unique $1.150\pm0.003$ d flux variation detected in Extreme Ultraviolet Explorer (EUVE) observations in the mid 1990s. The variation has eluded a satisfactory explanation, but hypotheses include channeled accretion producing a dark spot of metals, occultation by a gas cloud from an evaporating planet, or heati…
The first results of a new survey are reported, which explores the 2nd data release of the ESA-Gaia mission, in order to search for stellar companions of (Community) TESS Objects of Interest and to characterize their properties. In total, 193 binary and 15 hierarchical triple star systems are presented, detected among 1391 target stars, which are located at distances closer than about 500pc around the Sun. The companions and the targets are equidistant and share a common proper motion, as it is expected for gravitationally bound stellar systems, proven with their accurate Gaia astrometry. The …
We characterize the magnetic activity of M dwarfs to provide the planet community with information on the energy input from the star; in particular, in addition to the frequency of optical flares directly observed with TESS, we aim at estimating the corresponding X-ray flare frequencies, making use of the small pool of known events observed simultaneously in both wavebands. We identified 112 M dwarfs with a TESS magnitude <= 11.5 for which TESS can probe the full habitable zone for transits. These 112 stars have 1276 two-minute cadence TESS light curves from the primary mission, which we searc…
The Transiting Exoplanet Survey Satellite (TESS) is conducting a two-year wide-field survey searching for transiting exoplanets around nearby bright stars that will be ideal for follow-up characterization. To facilitate studies of planet compositions and atmospheric properties, accurate and precise planetary radii need to be derived from the transit light curves. Since 40 - 50% of exoplanet host stars are in multiple star systems, however, the observed transit depth may be diluted by the flux of a companion star, causing the radius of the planet to be underestimated. High angular resolution im…
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-degree radius centered 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 ($T_{\rm eff}$, $\log g$, [Fe/H], $v \si…
The T16 Planet Hunt: 10,000 New Planet Candidates from TESS Cycle 1 and the Confirmation of a Hot Jupiter Around TIC 183374187
Princeton University（普林斯顿大学）；University of California Los Angeles（加州大学洛杉矶分校）；Carnegie Science Observatories（卡内基科学天文台）；Universidad de Concepción（康塞普西翁大学）；Carnegie Institution for Science（卡内基科学学会）
We present a new analysis of the light curve of the young planet-hosting star TOI 451 in the light of new observations from TESS Cycle 3. Our joint analysis of the transits of all three planets, using all available TESS data, results in an improved ephemeris for TOI 451 b and TOI 451 c, which will help to plan follow-up observations. The updated mid-transit times are $\textrm{BJD}-2,457\,000=$ $1410.9896_{ - 0.0029 }^{ + 0.0032 }$, $1411.7982_{-0.0020}^{+0.0022}$, and $1416.63407_{-0.00100}^{+0.00096}$ for TOI 451 b, c, and d, respectively, and the periods are $1.8587028_{-10e-06}^{+08e-06}$, …
We present a study of the M dwarf exoplanetary systems forthcoming from NASA's TESS mission. While the mission's footprint is too complex to be characterized by a single detection completeness, we extract an ensemble completeness function that recovers the M dwarf planet detections from previous work. We employ this completeness function, together with a dual-population planet occurrence model that includes compact multiple planetary systems, to infer anew the planet yield. We predict both the number of M dwarf planets likely from TESS and their system architectures. We report four main findin…
Uninterrupted observations from space-borne telescopes provide the photometric precision that is required to detect shallow transits of small planets missed by ground-based surveys. We used data from the Transiting Exoplanet Survey Satellite (TESS) to search for nearby planetary companions in 12 planetary systems with hot Jupiters: HD 2685, Qatar-10, WASP-4, WASP-48, WASP-58, WASP-91, WASP-120, WASP-121, WASP-122, WASP-140, XO-6, and XO-7. We also applied the transit timing method based on homogeneously determined mid-transit times in order to search for non-transiting companions that could gr…
TOI-6692b: An eccentric 130 day period giant planet with a single transit from TESS
Center for Astrophysics | Harvard & Smithsonian（天体物理中心 | 哈佛-史密森尼）；University of Southern Queensland, Centre for Astrophysics（昆士兰大学南方分校，天体物理中心）；Department of Astronomy and Astrophysics, University of California, Santa Cruz（加州大学圣克鲁兹分校天文与天体物理学系）；Amateur Astronomer（业余天文学家）；Brorfelde Observatory（布罗费尔德天文台）；Citizen scientist, c/o Zooniverse, Department of Physics, University of Oxford（公民科学家，通过Zooniverse，牛津大学物理系）
RV$\times$TESS I: Modeling Asteroseismic Signals with Simultaneous Photometry and RVs
Tsinghua University（清华大学）；University of Hawai‘i（夏威夷大学）；University of Sydney（悉尼大学）；Shanghai Jiao Tong University（上海交通大学）；Australian National University（澳大利亚国立大学）；King’s College London（伦敦国王学院）；California Institute of Technology（加州理工学院）；Carnegie Institution for Science（卡内基科学研究所）；University of Southern Queensland（南昆士兰大学）
We present the latest results of our ongoing multiplicity study of (Community) TESS Objects of Interest, using astro- and photometric data from the ESA-Gaia mission, to detect stellar companions of these stars and to characterize their properties. In total, 113 binary, 5 hierarchical triple star systems, as well as one quadruple system were detected among 585 targets surveyed, which are all located at distances closer than about 500pc around the Sun. As proven with their accurate Gaia EDR3 astrometry the companions and the targets are located at the same distance and share a common proper moti…
We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, $V=13.07$, $K_s=8.204$, $R_s$=0.374 R$_{\odot}$, $M_s$=0.401 M$_{\odot}$, d=22 pc). The two planet candidates are identified in a single TESS sector and are validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of $P_b=0.77$ days, $P_c=12.25$ days and sizes $r_{p,b}=1.33\pm 0.07$ R$_{\oplus}$, $r_{p,c}=2.30\pm 0.16$ R$_{\oplus}$, the two planets span the radius valley in period-radius space around …
We present the confirmation and characterization of three hot Jupiters, TOI-1181b, TOI-1516b, and TOI-2046b, discovered by the TESS space mission. The reported hot Jupiters have orbital periods between 1.4 and 2.05 days. The masses of the three planets are $1.18\pm0.14$ M$_{\mathrm{J}}$, $3.16\pm0.12$\, M$_{\mathrm{J}}$, and 2.30 $\pm 0.28$ M$_{\mathrm{J}}$, for TOI-1181b, TOI-1516b, and TOI-2046b, respectively. The stellar host of TOI-1181b is a F9IV star, whereas TOI-1516b and TOI-2046b orbit F main sequence host stars. The ages of the first two systems are in the range of 2-5 Gyrs. However,…
We report the detection of a hot Jupiter ($M_{p}=1.75_{-0.17}^{+0.14}\ M_{J}$, $R_{p}=1.38\pm0.04\ R_{J}$) orbiting a middle-aged star ($\log g=4.152^{+0.030}_{-0.043}$) in the Transiting Exoplanet Survey Satellite (TESS) southern continuous viewing zone ($β=-79.59^{\circ}$). We confirm the planetary nature of the candidate TOI-150.01 using radial velocity observations from the APOGEE-2 South spectrograph and the Carnegie Planet Finder Spectrograph, ground-based photometric observations from the robotic Three-hundred MilliMeter Telescope at Las Campanas Observatory, and Gaia distance estimates…
We present the discovery of two new hot Jupiters identified from the WASP survey, WASP-186b and WASP-187b (TOI-1494.01 and TOI-1493.01). Their planetary nature was established from SOPHIE spectroscopic observations, and additional photometry was obtained from TESS. Stellar parameters for the host stars are derived from spectral line, IRFM, and isochrone placement analyses. These parameters are combined with the photometric and radial velocity data in an MCMC method to determine the planetary properties. WASP-186b is a massive Jupiter (4.22 +/- 0.18 M_J, 1.11 +/-0.03 R_J) orbiting a mid-F star …
Ephemeris Refinement for Qatar-4 b, HAT-P-18 b, and CoRoT-1 b with Small Telescope and TESS Observations
Arizona State University（亚利桑那州立大学）；NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory (Code 667)（NASA戈达德太空飞行中心系外行星与恒星天体物理学实验室）
SOAR TESS Survey III: Mapping the Stellar Companion Deficit around TESS Planet Candidates
Stephen F. Austin State University（斯蒂芬·F·奥斯汀州立大学）；Cerro Tololo Inter-American Observatory/NSF’s NOIRLab（塞罗托洛洛美洲际天文台/美国国家科学基金会NOIRLab）；The University of North Carolina at Chapel Hill（北卡罗来纳大学教堂山分校）
We report the discovery of four transiting giant planets around K dwarfs. The planets HATS-47b, HATS-48Ab, HATS-49b, and HATS-72b have masses of $0.369_{-0.021}^{+0.031}$ $M_{J}$, $0.243_{-0.030}^{+0.022}$ $M_{J}$, $0.353_{-0.027}^{+0.038}$ $M_{J}$ and $0.1254\pm0.0039$ $M_{J}$, respectively, and radii of $1.117\pm0.014$ $R_{J}$, $0.800\pm0.015$ $R_{J}$, $0.765\pm0.013$ $R_{J}$, and $0.7224\pm0.0032$ $R_{J}$, respectively. The planets orbit close to their host stars with orbital periods of $3.9228$ d, $3.1317$ d, $4.1480$ d and $7.3279$ d, respectively. The hosts are main sequence K dwarfs wit…
We present a new {\em Spitzer} transit observation of K2$-$28b, a sub-Neptune ($R_{\rm p} = 2.45\pm0.28 R_{Earth}$) orbiting a relatively bright ($V_{\rm mag} = 16.06$, $K_{\rm mag} = 10.75$) metal-rich M4 dwarf (EPIC 206318379). This star is one of only seven with masses less than 0.2 M_{Sun} known to host transiting planets, and the planet appears to be a slightly smaller analogue of GJ 1214b ($2.85\pm0.20 R_{Earth}$; \citealt{2013A&A...549A..10H}). Our new {\em Spitzer} observations were taken two years after the original K2 discovery data and have a significantly higher cadence, allowing u…
55 Cnc e is in a 0.73 day orbit transiting a Sun-like star. It has been observed that the occultation depth of this Super-Earth, with a mass of 8$M_{\bigoplus}$ and radius of 2$R_{\bigoplus}$, changes significantly over time at mid-infrared wavelengths. Observations with Spitzer measured a change in its day-side brightness temperature of 1200 K, possibly driven by volcanic activity, magnetic star-planet interaction, or the presence of a circumstellar torus of dust. Previous evidence for the variability in occultation was in the infrared range. Here we aim to explore if the variability exists a…
We report the discovery and confirmation of the planetary system TOI-1288. This late G dwarf harbours two planets: TOI-1288 b and TOI-1288 c. We combine TESS space-borne and ground-based transit photometry with HARPS-N and HIRES high-precision Doppler measurements, which we use to constrain the masses of both planets in the system and the radius of planet b. TOI-1288~b has a period of $2.699835^{+0.000004}_{-0.000003}$ d, a radius of $5.24 \pm 0.09$ R$_\oplus$, and a mass of $42 \pm 3$ M$_\oplus$, making this planet a hot transiting super-Neptune situated right in the Neptunian desert. This de…
