.@NASA_TESS remains in Coarse Pointing Inertial, all subsystems are nominal. #TESS continues to make contact with the Deep Space Network. The on-board orbit propagator was initialized and is now running. Additional observatory subsystems are planned for check out today.
.@NASA_TESS successfully completed the first perigee maneuver (PM1). Initial indications are that the burn was nominal. P1M is the second of six on orbit burns for #TESS to reach its final science orbit.
.@NASA_TESS Mission Update: The Ka-band transmitter and Traveling Wave Tube Amplifier were turned on. @NASASCaN's Deep Space Network successfully locked on to the Ka signal immediately. The link showed a strong link margin with no errors.
.@NASA_TESS Mission Update: The #TESS ADHU (data handling unit computer for the instrument from @SEAKR_Eng) was turned on. Checkout confirmed all nominal. #TESS sent data from the ADHU to the Ka Transmitter and received packets at DSN without errors.
TESS is approaching its second apogee - at 1903 UTC today it will be 353440 km above the Earth's surface and start on the downward arc of its second orbit.
.@NASA_TESS Mission Update: Team decided that the second apogee maneuver (Apogee 2 maneuver (A2M)), was not necessary based on the good system performance during the first two maneuvers. Spacecraft subsystems continue to operate nominally.
We present new gravity and limb-darkening coefficients for a wide range of effective temperatures, gravities, metallicities, and microturbulent velocities. These coefficients can be used in many different fields of stellar physics as synthetic light curves of eclipsing binaries and planetary transits, stellar diameters, line profiles in rotating stars, and others. The limb-darkening coefficients were computed specifically for the photometric system of the space mission TESS and were performed by adopting the least-square method. In addition, the linear and bi-parametric coefficients, by adopting the flux conservation method, are also available. On the other hand, to take into account the effects of tidal and rotational distortions, we computed the passband gravity-darkening coefficients y(λ) using a general differential equation in which we consider the effects of convection and of the partial derivative (∂lnI(λ)/∂lng)Teff. To generate the limb-darkening coefficients we adopt two stellar atmosphere models: ATLAS (plane-parallel) and PHOENIX (spherical, quasi-spherical, and r-method). The specific intensity distribution was fitted using five approaches: linear, quadratic, square root, logarithmic, and a more general one with four terms. These grids cover together 19 metallicities ranging from 10−5 up to 10+1 solar abundances, 0 ≤ log g ≤ 6.0 and 1500 K ≤ Teff ≤ 50000 K. The calculations of the gravity-darkening coefficients were performed for all plane-parallel ATLAS models.
Quote.@NASA_TESS Mission Update: Team decided that the second apogee maneuver (Apogee 2 maneuver (A2M)), was not necessary based on the good system performance during the first two maneuvers. Spacecraft subsystems continue to operate nominally.https://twitter.com/nasa_tess/status/990743720566894594
.@NASA_TESS Mission Update: The four cameras for #TESS are now powered on and will begin collecting data for the calibration process which will last until mid June.
Quote from: FutureSpaceTourist on 04/30/2018 06:33 amQuote.@NASA_TESS Mission Update: Team decided that the second apogee maneuver (Apogee 2 maneuver (A2M)), was not necessary based on the good system performance during the first two maneuvers. Spacecraft subsystems continue to operate nominally.https://twitter.com/nasa_tess/status/990743720566894594So, basically, TESS's main propulsion system is working better than expected; that's good to know!
Given recent events on Kepler, it seems like a good idea to start looking at the replacement missions. So here is a starter on TESS.There is a reasonable summary from Ricker et al here: https://arxiv.org/abs/1406.0151Overview of the orbit design: hereLatest expected science yield (numbers of planets detected, etc): https://arxiv.org/abs/1804.05050Main archive page: hereNote: I will update this post to add further links to the archive manual, target catalogues, etc as they become available.--- Tony
The MIT-led Transiting Exoplanet Survey Satellite (TESS) has a goal of detecting terrestrial-mass planets orbiting stars bright enough for mass determination via ground-based radial velocity observations. Here we present estimates of how many exoplanets the TESS mission will detect, physical properties of the detected planets, and the properties of the stars that those planets orbit. This work uses stars drawn from the TESS Input Catalog Candidate Target List and revises yields from prior studies that were based on Galactic models. We model the TESS observing strategy to select approximately 200,000 stars at 2-minute cadence, while the remaining stars are observed at 30-min cadence in full-frame image data. We place zero or more planets in orbit around each star, with physical properties following measured exoplanet occurrence rates, and use the TESS noise model to predict the derived properties of the detected exoplanets. In the TESS 2-minute cadence mode we estimate that TESS will find 1250 ± 70 exoplanets (90% confidence), including 250 smaller than 2 Earth-radii. Furthermore, we predict an additional 3200 planets will be found in full-frame image data orbiting bright dwarf stars and more than 10,000 around fainter stars. We predict that TESS will find 500 planets orbiting M-dwarfs, but the majority of planets will orbit stars larger than the Sun. Our simulated sample of planets contains hundreds of small planets amenable to radial velocity follow-up, potentially more than tripling the number of planets smaller than 4 Earth-radii with mass measurements. This sample of simulated planets is available for use in planning follow-up observations and analyses.
Resumiendo, TESS descubrirá cerca de 15.000 planetas extrasolares, pero solo 4.500 serán de “calidad”, o sea, podrán ser analizados en profundidad más adelante usando otros instrumentos, que es el objetivo prioritario de la misión. Pero lo más fascinante es que muchos estarán alrededor de estrellas brillantes, algunas de las cuales se podrán ver a simple vista o con unos simples prismáticos. Dentro de poco será muy común mirar al cielo, señalar una estrella casi al azar y decir “ahí hay un planeta”. Y todo gracias a TESS.In summary, TESS will discover around 15 thousand extrasolar planets, but only 4500 will be "high-quality"; that is, will be amenable to in-depth further analyses using other instruments - which is the mission's objective. The most fascinating thing, however, is that many will be orbiting brighter stars, some of which can be seen with the naked eye or with some simple binoculars. Soon, it will be common to look at the sky, point almost randomly at a star and say "there is a planet there". All thanks to TESS.
That paper is linked in the top post
.@NASA_TESS Mission Update: The #TESS team were successful in putting TESS in Fine Pointing Mode (instrument supplying quaternions) for the first time as part of instrument commissioning.
.@NASA_TESS Mission Update: #TESS continued fine pointing data collection for instrument calibration. The #TESS cameras are being slowly cooled to their operating temperature of -80°C.
.@NASA_TESS Mission Update: completed the P2M (Perigee 2 Maneuver), another on orbit burn to place #TESS into its final science orbit, nominally. The instrument is turned off for all maneuvers. While this maneuver is only for 7 secs it puts TESS on target for our lunar encounter.
We present a semi-analytic estimate of the expected yield of single-transit planets from the Transiting Exoplanet Survey Satellite (TESS). We use the TESS Candidate Target List 6 (CTL-6) as an input catalog of over 4 million sources. We predict that from the 200,000 stars selected to be observed with the high-cadence postage stamps with the highest CTL-6 priority, there will be 241 single-transit events caused by planets detectable at a signal-to-noise ratio of SNR≥7.3. We find a lower limit of an additional 977 events caused by single-transit planets in the full frame images (FFI); this is a lower limit because the CTL-6 is incomplete below a TESS magnitude of T>12. Of the single-transit events from the postage stamps and FFIs, 1091/1218 will have transit depths deeper than 0.1%, and will thus be amenable for photometric follow-up from the ground, and 1195/1218 will have radial velocity signals greater than 1 m/s. We estimate that the periods of 146 single transits will be constrained to better than 10% using the TESS photometry assuming circular orbits. We find that the number of planets detected by TESS in the postage stamps with periods P>25 days will be doubled by including single-transiting planets, while the number of planets with P>250 days will be increased by an order of magnitude. We predict 79 habitable zone planets from single-transits, with 18 orbiting FGK stars.
.@NASA_TESS Mission Update: After P2M (Perigee 2 Maneuver) was completed, the spacecraft is in Coarse Pointing Inertial mode. Pointing is stable and all spacecraft systems are nominal. The cameras are on and taking data, and are continuing cooling to approximately -85C.
.@NASA_TESS Mission Update: The spacecraft is in Coarse Pointing Inertial mode, with the instrument ensemble boresight at -54deg pitch. Battery is healthy and between 33.1-33.3V. No spacecraft activities yesterday, the cameras are on and taking data, and have reached -85C ± 1C.
.@NASA_TESS Mission Update: Perigee 3 Maneuver (P3M) was completed successfully with nominal performance from the thrusters. #TESS is on its way to a lunar flyby at 06:34:35 UTC on 17th May. @NASAMoon here we come!