TESS: NASA/MIT Mission Will Search For Habitable Planets

[mjimih]

http://www.forbes.com/sites/alexknapp/2 ... e-planets/

Sounds exciting doesn't it? Bring 'em on!

"NASA announced on Friday that it will be granting $200 million in funding to MIT’s Transiting Exoplanet Survey Satellite (TESS). The goals of TESS are straightforward, but hard to do: they’ll be widening by a huge order of magnitude the search for planets outside our solar system...."

[bystander]

Artist's rendering of TESS in orbit -- Illustration: Chet Beals/MIT Lincoln Lab

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NASA selects MIT-led TESS project for 2017 mission
Massachusetts Institute of Technology | 2013 Apr 05

Kepler 2.0: Next-Gen Exoplanet Hunter Approved
Discovery News | Ian O'Neil | 2013 Apr 07

TESS: A Full-Sky Exoplanet Survey
Centauri Dreams | Paul Gilster | 2013 Apr 08

NASA Picks Next Exoplanet Mission for Launch in 2017
Science Insider | Yudhijit Bhattacharjee | 2013 Apr 08

[mjimih]

The best part about TESS is that it will excel at finding Earth sized rocks in habitable zones.

[neufer]

<<TESS of the d'Urbervilles is commonly believed to be the most depressing book ever written in the English language. Hardy's writing often illustrates the "ache of modernism", and this theme is notable in TESS, which, as one critic noted, portrays "the energy of traditional ways and the strength of the forces that are destroying them". Hardy describes modern farm machinery with infernal imagery; also, at the dairy, he notes that the milk sent to the city must be watered down because the townspeople cannot stomach whole milk. Angel's middle-class fastidiousness makes him reject TESS, a woman whom Hardy often portrays as a sort of Wessex Eve, in harmony with the natural world. When he parts from her and goes to Brazil, the handsome young man gets so ill that he is reduced to a "mere yellow skeleton". All these instances are typically interpreted as indications of the negative consequences of man's separation from nature, both in the creation of destructive machinery and in the inability to rejoice in pure nature.

At the end, when TESS and Angel come to Stonehenge, commonly believed in Hardy's time to be a pagan temple, she willingly lies down on an altar, thus fulfilling her destiny as a human sacrifice. This symbolism may help explain TESS as a personification of nature — lovely, fecund, and exploitable — while animal imagery throughout the novel strengthens the association. Examples are numerous: TESS's misfortunes begin when she falls asleep while driving Prince to market, thus causing the horse's death; at Trantridge, she becomes a poultry-keeper; she and Angel fall in love amid cows in the fertile Froom valley; and on the road to Flintcombe-Ashe, she kills some wounded pheasants to end their suffering.>>

[mjimih]

http://en.wikipedia.org/wiki/Transiting ... _Satellite

Once launched, the telescope would conduct a two-year all-sky survey program for exploring transiting exoplanets around nearby and bright stars.[1] TESS would be equipped with four wide-angle telescopes and charge-coupled device (CCD) detectors, with a total size of 192 megapixels. Science data will be processed and stored for three months onboard, and only data of interest will be transmitted to Earth for further analysis. Data collected by the spacecraft are also stored for three months, enabling astrophysicists to search the data for an unexpected, transient phenomenon, such as a gamma-ray burst.

The survey will focus on G- and K- type stars with apparent magnitudes brighter than 12.[5] Approximately 2 million of these stars would be studied, including the 1,000 closest red dwarfs. TESS is predicted to discover 1,000 - 10,000 transiting exoplanet candidates which are Earth-sized or larger, with orbital periods of up to two months. These candidates could be later investigated by the HARPS spectrometer and the future James Webb Space Telescope. The development team at MIT is so optimistic about the mission that they have suggested that the first manned interstellar space missions may be to planets discovered by TESS.

[mjimih]

On a cosmological timescale, The Earth's period of habitability is nearly over
http://spacefellowship.com/news/art1165 ... -over.html

2009 article

Edward Guinan, a professor of astronomy and astrophysics at Villanova University in the USA, and his “Sun-in-Time” project team have studied stars that are analogues of the Sun at both early and late stages of its lifecycle. These “solar proxies” enable scientists to look through a window in time to see the harsh conditions prevailing in the early or future Solar System, as well as in planetary systems around other stars. These studies could lead to profound insights into the origin of life on Earth and reveal how likely (or unlikely) the rise of life is elsewhere in the cosmos. This work has revealed that the Sun rotated more than ten times faster in its youth (over four billion years ago) than today. The faster a star rotates, the harder the magnetic dynamo at its core works, generating a stronger magnetic field, so the young Sun emitted X-rays and ultraviolet radiation up to several hundred times stronger than the Sun today.

Guinan explains a surprising realisation that emerged from their work: “The Sun does not seem like the perfect star for a system where life might arise. Although it is hard to argue with the Sun’s ‘success’ as it so far is the only star known to host a planet with life, our studies indicate that the ideal stars to support planets suitable for life for tens of billions of years may be a smaller slower burning ‘orange dwarf’ with a longer lifetime than the Sun ― about 20-40 billion years. These stars, also called K stars, are stable stars with a habitable zone that remains in the same place for tens of billions of years. They are 10 times more numerous than the Sun, and may provide the best potential habitat for life in the long run”. He continues: “On the more speculative side we have also found indications that planets like Earth are also not necessarily the best suited for life to thrive. Planets two to three times more massive than the Earth, with a higher gravity, can retain the atmosphere better. They may have a larger liquid iron core giving a stronger magnetic field that protects against the early onslaught of cosmic rays. Furthermore, a larger planet cools more slowly and maintains its magnetic protection. This kind of planet may be more likely to harbour life. I would not trade though ― you can’t argue with success”.

Before I thought looking for a star like the Sun was the best way to find another Earth. But it looks like there are several reasons why TESS is looking at G & K stars. One being they are hot and bright enough for further analysis by ground based scopes where as the data from Kepler is not as helpful in that regard.

[neufer]

Click to play embedded YouTube video.

[bystander]

NASA Prepares to Launch Next Mission to Search Sky for New Worlds
NASA | GSFC | TESS | 2018 Mar 28

Click to play embedded YouTube video.

NASA’s Transiting Exoplanet Survey Satellite (TESS) is undergoing final preparations in Florida for its April 16 launch to find undiscovered worlds around nearby stars, providing targets where future studies will assess their capacity to harbor life.

“One of the biggest questions in exoplanet exploration is: If an astronomer finds a planet in a star’s habitable zone, will it be interesting from a biologist's point of view?” said George Ricker, TESS principal investigator at the Massachusetts Institute of Technology (MIT) Kavli Institute for Astrophysics and Space Research in Cambridge, which is leading the mission. “We expect TESS will discover a number of planets whose atmospheric compositions, which hold potential clues to the presence of life, could be precisely measured by future observers.”

On March 15, the spacecraft passed a review that confirmed it was ready for launch. For final launch preparations, the spacecraft will be fueled and encapsulated within the payload fairing of its SpaceX Falcon 9 rocket.

TESS will launch from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida. With the help of a gravitational assist from the Moon, the spacecraft will settle into a 13.7-day orbit around Earth. Sixty days after launch, and following tests of its instruments, the satellite will begin its initial two-year mission.

Four wide-field cameras will give TESS a field-of-view that covers 85 percent of our entire sky. Within this vast visual perspective, the sky has been divided into 26 sectors that TESS will observe one by one. The first year of observations will map the 13 sectors encompassing the southern sky, and the second year will map the 13 sectors of the northern sky.

The spacecraft will be looking for a phenomenon known as a transit, where a planet passes in front of its star, causing a periodic and regular dip in the star’s brightness. NASA’s Kepler spacecraft used the same method to spot more than 2,600 confirmed exoplanets, most of them orbiting faint stars 300 to 3,000 light-years away. ...

[bystander]

TESS Readies for Takeoff
Massachusetts Institute of Technology | 2018 Apr 12

Satellite developed by MIT aims to discover thousands of nearby exoplanets, including at least 50 Earth-sized ones.

There are potentially thousands of planets that lie just outside our solar system — galactic neighbors that could be rocky worlds or more tenuous collections of gas and dust. Where are these closest exoplanets located? And which of them might we be able to probe for clues to their composition and even habitability? The Transiting Exoplanet Survey Satellite (TESS) will be the first to seek out these nearby worlds.

The NASA-funded spacecraft, not much larger than a refrigerator, carries four cameras that were conceived, designed, and built at MIT, with one wide-eyed vision: to survey the nearest, brightest stars in the sky for signs of passing planets.

Now, more than a decade since MIT scientists first proposed the mission, TESS is about to get off the ground. The spacecraft is scheduled to launch on a SpaceX Falcon 9 rocket from Cape Canaveral Air Force Station in Florida, no earlier than April 16, at 6:32 p.m. EDT. ...

NASA TV to Air Launch of TESS
NASA | TESS | 2018 Apr 11

[neufer]

Click to play embedded YouTube video.

[bystander]

NASA Planet Hunter on Its Way to Orbit
NASA | GSFC | KSC | TESS | 2018 Apr 18

NASA’s next planet-hunter, the Transiting Exoplanet Survey Satellite (TESS), successfully launched on a SpaceX Falcon 9 on April 18, 2018. TESS will search for new worlds outside our solar system for further study. (Credits: NASA Television)

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NASA’s Transiting Exoplanet Survey Satellite (TESS) launched on the first-of-its-kind mission to find worlds beyond our solar system, including some that could support life.

TESS, which is expected to find thousands of new exoplanets orbiting nearby stars, lifted off at 6:51 p.m. EDT Wednesday on a SpaceX Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida. At 7:53 p.m., the twin solar arrays that will power the spacecraft successfully deployed. ...

Over the course of several weeks, TESS will use six thruster burns to travel in a series of progressively elongated orbits to reach the Moon, which will provide a gravitational assist so that TESS can transfer into its 13.7-day final science orbit around Earth. After approximately 60 days of check-out and instrument testing, the spacecraft will begin its work. ...

For this two-year survey mission, scientists divided the sky into 26 sectors. TESS will use four unique wide-field cameras to map 13 sectors encompassing the southern sky during its first year of observations and 13 sectors of the northern sky during the second year, altogether covering 85 percent of the sky. ...

TESS to Uncover the Secrets of Stars and Exoplanets
Institute for Astronomy | University of Hawaii | 2018 Apr 18

[bystander]

New Planet Hunter Snaps Initial Test Image,
Swings by Moon Toward Final Orbit
NASA | GSFC | TESS | 2018 May 18

This test image from one of the four cameras aboard the Transiting Exoplanet Survey Satellite (TESS) captures a swath of the southern sky along the plane of our galaxy. TESS is expected to cover more than 400 times the amount of sky shown in this image when using all four of its cameras during science operations. (Credits: NASA/MIT/TESS)

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NASA’s next planet hunter, the Transiting Exoplanet Survey Satellite (TESS), is one step closer to searching for new worlds after successfully completing a lunar flyby on May 17. The spacecraft passed about 5,000 miles from the Moon, which provided a gravity assist that helped TESS sail toward its final working orbit.

As part of camera commissioning, the science team snapped a two-second test exposure using one of the four TESS cameras. The image, centered on the southern constellation Centaurus, reveals more than 200,000 stars. The edge of the Coalsack Nebula is in the right upper corner and the bright star Beta Centauri is visible at the lower left edge. TESS is expected to cover more than 400 times as much sky as shown in this image with its four cameras during its initial two-year search for exoplanets. A science-quality image, also referred to as a “first light” image, is expected to be released in June.

TESS will undergo one final thruster burn on May 30 to enter its science orbit around Earth. This highly elliptical orbit will maximize the amount of sky the spacecraft can image, allowing it to continuously monitor large swaths of the sky. TESS is expected to begin science operations in mid-June after reaching this orbit and completing camera calibrations. ...

Click to play embedded YouTube video.

The Unique Orbit of NASA’s Newest Planet Hunter -- Credit: NASA/GSFC

[bystander]

Nearly 80 Exoplanet Candidates Identified in Record Time
Massachusetts Institute of Technology | 2018 Jun 21

Search considered successful “dress rehearsal” for exoplanet hunter TESS.

Scientists at MIT and elsewhere have analyzed data from K2, the follow-up mission to NASA’s Kepler Space Telescope, and have discovered a trove of possible exoplanets amid some 50,000 stars.

In a paper that appears online today in The Astronomical Journal, the scientists report the discovery of nearly 80 new planetary candidates, including a particular standout: a likely planet that orbits the star HD 73344, which would be the brightest planet host ever discovered by the K2 mission.

The planet appears to orbit HD 73344 every 15 days, and based on the amount of light that it blocks each time it passes in front of its star, scientists estimate that the planet is about 2.5 times the size of the Earth and 10 times as massive. It is also likely incredibly hot, with a temperature somewhere in the range of 1,200 to 1,300 degrees Celsius, or around 2,000 degrees Fahrenheit — about the the temperature of lava from an erupting volcano.

The planet lies at a relatively close distance of 35 parsecs, or about 114 light years from Earth. Given its proximity and the fact that it orbits a very bright star, scientists believe the planet is an ideal candidate for follow-up studies to determine its atmospheric composition and other characteristics. ...

The new analysis is also noteworthy for the speed with which it was performed. The researchers were able to use existing tools developed at MIT to rapidly search through graphs of light intensity called “lightcurves” from each of the 50,000 stars that K2 monitored in its two recent observing campaigns. They quickly identified the planetary candidates and released the information to the astronomy community just weeks after the K2 mission made the spacecraft’s raw data available. A typical analysis of this kind takes between several months and a year. ...

Planetary Candidates from K2 Campaign 16 - Liang Yu et al

• Astronomical Journal 156(1):22 (July 2018) DOI: 10.3847/1538-3881/aac6e6
  arXiv.org > astro-ph > arXiv:1803.04091 > 12 Mar 2018 (v1), 23 May 2018 (v3)

A TESS Dress Rehearsal: Planetary Candidates and Variables from K2 Campaign 17 - Ian J. M. Crossfield et al

• arXiv.org > astro-ph > arXiv:1806.03127 > 08 Jun 2018

[bystander]

TESS Shares First Science Image in Hunt to Find New Worlds
NASA | GSFC | TESS | 2018 Sep 17

Credits: NASA/MIT/TESS

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NASA’s newest planet hunter, the Transiting Exoplanet Survey Satellite {TESS), is now providing valuable data to help scientists discover and study exciting new exoplanets, or planets beyond our solar system. Part of the data from TESS’ initial science orbit includes a detailed picture of the southern sky taken with all four of the spacecraft’s wide-field cameras. This “first light” science image captures a wealth of stars and other objects, including systems previously known to have exoplanets. ...

TESS acquired the image using all four cameras during a 30-minute period on Tuesday, Aug. 7. The black lines in the image are gaps between the camera detectors. The images include parts of a dozen constellations, from Capricornus to Pictor, and both the Large and Small Magellanic Clouds, the galaxies nearest to our own. The small bright dot above the Small Magellanic Cloud is a globular cluster — a spherical collection of hundreds of thousands of stars — called NGC 104, also known as 47 Tucanae because of its location in the southern constellation Toucana, the Toucan. Two stars, Beta Gruis and R Doradus, are so bright they saturate an entire column of pixels on the detectors of TESS’s second and fourth cameras, creating long spikes of light. ...

TESS’s cameras, designed and built by MIT’s Lincoln Laboratory in Lexington, Massachusetts, and the MIT Kavli Institute, monitor large swaths of the sky to look for transits. Transits occur when a planet passes in front of its star as viewed from the satellite’s perspective, causing a regular dip in the star’s brightness.

TESS will spend two years monitoring 26 such sectors for 27 days each, covering 85 percent of the sky. During its first year of operations, the satellite will study the 13 sectors making up the southern sky. Then TESS will turn to the 13 sectors of the northern sky to carry out a second year-long survey. ...

[bystander]

MuSCAT2 to Find Earth-like Planets in the TESS Era
National Institutes of Natural Sciences | Astrobiology Center
National Astronomical Observatory of Japan | 2018 Dec 17

Newly developed simultaneous multi-color camera MuSCAT2 on the 1.52-m Telescopio Carlos Sánchez at the Teide Observatory, Canaries, Spain. Credit: NINS Astrobiology Center

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A Japan-Spain team has developed a powerful 4-color simultaneous camera named MuSCAT2 for the 1.52-m Telescopio Carlos Sánchez at the Teide Observatory, Canaries, Spain. The instrument aims to find a large number of transiting exoplanets, including Earth-like habitable planets orbiting stars near the Sun, in collaboration with NASA’s Transiting Exoplanet Survey Satellite (TESS) launched in April 2018.

In April 2018, NASA launched a new satellite named Transiting Exoplanet Survey Satellite (TESS) to discover new exoplanets around stars near the Sun. TESS finds exoplanets by observing planetary transits, a phenomenon in which a planet passes in front of its host star and blocks part of the star's light. Transiting exoplanets are especially valuable targets for exoplanet studies, since they provide information about the true mass, radius, density, orbital obliquity, and atmosphere of such planets.

However, transiting exoplanet candidates discovered by TESS are not always real planets. An eclipsing binary, a pair of stars orbiting and eclipsing each other, can also produce transit-like signals. For the TESS mission, the false positive rate caused by eclipsing binaries is predicted to be 30-70% depending on the direction observed. Follow up observations can help distinguish actual exoplanets from false positives.

Multi-color transit observations are one way to separate exoplanets from eclipsing binary stars. This is because in the case of an eclipsing binary, the light coming from the system changes color as it dims, while for an exoplanet transit the light stays the same color as it dims. ...

[neufer]

MuSCAT2 to Find Earth-like Planets in the TESS Era
National Institutes of Natural Sciences | Astrobiology Center
National Astronomical Observatory of Japan | 2018 Dec 17

Click to play embedded YouTube video.

<<Transiting exoplanet candidates discovered by TESS are not always real planets. An eclipsing binary, a pair of stars orbiting and eclipsing each other, can also produce transit-like signals. For the TESS mission, the false positive rate caused by eclipsing binaries is predicted to be 30-70% depending on the direction observed. Follow up observations can help distinguish actual exoplanets from false positives.

Multi-color transit observations are one way to separate exoplanets from eclipsing binary stars. This is because in the case of an eclipsing binary, the light coming from the system changes color as it dims, while for an exoplanet transit the light stays the same color as it dims.>>

[bystander]

TESS Rounds Up Its First Planets,
Snares Far-Flung Supernovae
NASA | Exoplanet Exploration | TESS | 2019 Jan 07

NASA’s Transiting Exoplanet Survey Satellite has found three confirmed exoplanets in the data from the space telescope’s four cameras. (Credit: NASA/MIT/TESS)

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NASA’s Transiting Exoplanet Survey Satellite (TESS) has found three confirmed exoplanets, or worlds beyond our solar system, in its first three months of observations.

The mission’s sensitive cameras also captured 100 short-lived changes — most of them likely stellar outbursts — in the same region of the sky. They include six supernova explosions whose brightening light was recorded by TESS even before the outbursts were discovered by ground-based telescopes.

The new discoveries show that TESS is delivering on its goal of discovering planets around nearby bright stars. Using ground-based telescopes, astronomers are now conducting follow-up observations on more than 280 TESS exoplanet candidates.

The first confirmed discovery is a world called Pi Mensae c about twice Earth’s size. Every six days, the new planet orbits the star Pi Mensae, located about 60 light-years away and visible to the unaided eye in the southern constellation Mensa. The bright star Pi Mensae is similar to the Sun in mass and size. ...

Next is LHS 3844b, a rocky planet about 1.3 times Earth’s size located about 49 light-years away in the constellation Indus, making it among the closest transiting exoplanets known. The star is a cool M-type dwarf star about one-fifth the size of our Sun. Completing an orbit every 11 hours, the planet lies so close to its star that some of its rocky surface on the daytime side may form pools of molten lava.

The third — and possibly fourth — planets orbit HD 21749, a K-type star about 80 percent the Sun’s mass and located 53 light-years away in the southern constellation Reticulum.

The confirmed planet, HD 21749b, is about three times Earth’s size and 23 times its mass, orbits every 36 days, and has a surface temperature around 300 degrees Fahrenheit (150 degrees Celsius). ... It is the longest-period transiting planet within 100 light-years of the solar system, and it has the coolest surface temperature of a transiting exoplanet around a star brighter than 10th magnitude, or about 25 times fainter than the limit of unaided human vision.

What’s even more exciting are hints the system holds a second candidate planet about the size of Earth that orbits the star every eight days. If confirmed, it could be the smallest TESS planet to date. ...

But in its month-long stare into each sector, TESS records many additional phenomena, including comets, asteroids, flare stars, eclipsing binaries, white dwarf stars and supernovae, resulting in an astronomical treasure trove. ...

TESS Discovers Its Third New Planet, with Longest Orbit Yet
Massachusetts Institute of Technology | 2019 Jan 07

NASA exoplanet hunter racks up bizarre worlds and exploding stars
Nature News | 2019 Jan 08

The Longest Period TESS Planet Yet: A Sub-Neptune Transiting A Bright, Nearby K Dwarf Star ~ Diana Dragomir et al

• arXiv.org > astro-ph > arXiv:1901.00051 > 31 Dec 2018

TESS Discovery of an ultra-short-period planet around the nearby M dwarf LHS 3844 ~ Roland Vanderspek et al

• arXiv.org > astro-ph > arXiv:1809.07242 > 19 Sep 2019

TESS Discovery of a Transiting Super-Earth in the π Mensae System ~ Chelsea X. Huang et al

• Astrophysical Journal Letters 868(2):L39 (2018 Dec 01) DOI: 10.3847/2041-8213/aaef91
  arXiv.org > astro-ph > arXiv:1809.05967 > 16 Sep 2018 (v1), 08 Nov 2018 (v2)

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<<Pi Mensae (π Men), also known as HD 39091, is a yellow dwarf star in the constellation of Mensa. This star has a high proper motion. The apparent magnitude is 5.67, which can be visible to the naked eye in exceptionally dark, clear skies. It is nearly 60 ly away. The star is slightly larger than the Sun in terms of mass, size, luminosity, temperature, and metallicity and is about 730 million years younger. It hosts two planets.

On October 15, 2001, an extrasolar planet was found orbiting the star. Pi Mensae b is one of the most massive planets ever discovered, and has a very eccentric orbit that takes approximately 2,151 days (5.89 years) to complete. Because of its eccentricity, and being a massive superjovian that passes through the habitable zone, it would have disrupted the orbits of any Earth-like planets, and possibly thrown them into the star, or out into the interstellar medium.

Incorporating more accurate Hipparcos data yields a mass range for the companion to be anywhere from 10.27 to 29.9 times that of Jupiter, confirming its substellar nature with the upper limit of mass putting it in the brown dwarf range. Pi Mensae was ranked 100th on the list of top 100 target stars for the planned (but now canceled) Terrestrial Planet Finder mission to search for Earth-like planets.

On September 16, 2018, a preprint was posted to arXiv detailing the discovery of a Super-Earth on a 6.27-day orbit around the star, the first exoplanet detection by the Transiting Exoplanet Survey Satellite (TESS) submitted for publication.>>

[bystander]

The hunt is on for closest Earth-like planets
Cornell University | 2019 Mar 26

Artists’ concept of the Transiting Exoplanet Survey Satellite against a background of stars and orbiting planets in the Milky Way. (Credit: ESA, ESO, & NASA GSFC)

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NASA’s new Transiting Exoplanet Survey Satellite (TESS) is designed to ferret out habitable exoplanets, but with hundreds of thousands of sunlike and smaller stars in its camera views, which of those stars could host planets like our own?

TESS will observe 400,000 stars across the whole sky to catch a glimpse of a planet transiting across the face of its star, one of the primary methods by which exoplanets are identified.

A team of astronomers from Cornell, Lehigh University and Vanderbilt University has identified the most promising targets for this search in the new “TESS Habitable Zone Star Catalog” ...

The catalog identifies 1,822 stars for which TESS is sensitive enough to spot Earth-like planets just a bit larger than Earth that receive radiation from their star equivalent to what Earth receives from our sun. For 408 stars, TESS can glimpse a planet just as small as Earth, with similar irradiation, in one transit alone. ...

TESS Habitable Zone Star Catalog ~ L. Kaltenegger et al

• Astrophysical Journal Letters 874(1):L8 (2019 Mar 20) DOI: 10.3847/2041-8213/ab0e8d

[bystander]

Data Flows from TESS Leads to Discovery of Saturn-Sized Planet
Iowa State University | 2019 Mar 27

A 'hot Saturn' passes in front of its host star in this illustration. Astronomers who study stars used 'starquakes' to characterize the star, which provided critical information about the planet. Illustration: Gabriel Perez Diaz, IAC

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Astronomers who study stars are providing a valuable assist to the planet-hunting astronomers pursuing the primary objective of NASA’s new TESS Mission.

In fact, asteroseismologists – stellar astronomers who study seismic waves (or “starquakes”) in stars that appear as changes in brightness – often provide critical information for finding the properties of newly discovered planets.

This teamwork enabled the discovery and characterization of the first planet identified by TESS for which the oscillations of its host star can be measured.

The planet – TOI 197.01 (TOI is short for “TESS Object of Interest”) – is described as a “hot Saturn” in a recently accepted scientific paper. That’s because the planet is about the same size as Saturn and is also very close to its star, completing an orbit in just 14 days, and therefore very hot. ...

A Hot Saturn Orbiting an Oscillating Late Subgiant Discovered by TESS ~ Daniel Huber et al

• arXiv.org > astro-ph > arXiv:1901.01643 > 07 Jan 2019

The Asteroseismic Target List for Solar-like Oscillators Observed in
2 minute Cadence with the Transiting Exoplanet Survey Satellite ~ Mathew Schofield et al

• Astrophysical Journal Supplement 241(1):12 (2019 Mar) DOI: 10.3847/1538-4365/ab04f5
• arXiv.org > astro-ph > arXiv:1901.10148 > 29 Jan 2019

[bystander]

TESS Finds Its First Earth-Sized Planet
Carnegie Institution for Science | 2019 Apr 15

Artist's conception of HD 21749c, the first Earth-sized planet found by TESS, as well as its sibling, HD 21749b, a warm sub-Neptune-sized world. (Credit: Robin Dienel/CIS)

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A nearby system hosts the first Earth-sized planet discovered by NASA’s Transiting Exoplanets Survey Satellite, as well as a warm sub-Neptune-sized world ...

“It’s so exciting that TESS, which launched just about a year ago, is already a game-changer in the planet-hunting business ... The spacecraft surveys the sky and we collaborate with the TESS follow-up community to flag potentially interesting targets for additional observations using ground-based telescopes and instruments.”

One such tool, the Planet Finder Spectrograph (PFS) on the Magellan II telescope at Carnegie’s Las Campanas Observatory in Chile, was a crucial component of this effort. It helped confirm the planetary nature of the TESS signal, and to measure the mass of the newly discovered sub-Neptune.

The PFS—built by Shectman and Crane using a method pioneered by Butler and his collaborators—works using a technique called the radial velocity method, which is currently the only way for astronomers to measure the masses of individual planets. Without known masses, it is very challenging to determine a planet’s density or its general chemical composition.

This method takes advantage of that fact that not only does a star’s gravity influence the planet orbiting it, but the planet’s gravity also affects the star in turn. The PFS enables astronomers to detect these tiny wobbles that the planet’s gravity induces in the star’s orbit. ...

TESS Discovers Its First Earth-Sized Planet
Massachusetts Institute of Technology | 2019 Apr 16

TESS Discovers Its First Earth-Sized Planet
NASA | Goddard | TESS | 2019 Apr 15

TESS Delivers Its First Earth-sized Planet and a Warm Sub-Neptune ~ Diana Dragomir et al

• Astrophysical Journal Letters 875(2):L7 (2019 Apr 20) DOI: 10.3847/2041-8213/ab12ed
• arXiv.org > astro-ph > arXiv:1901.00051 > 31 Dec 2018 (v1), 15 Apr 2019 (v2)

[bystander]

TESS First Light on Stellar Physics
Institute of Astrophysics and Space Sciences | University of Porto | 2019 Jun 06

Among the 32,000 stars observed in short cadence in the first two months of science operations, asteroseismic data from the TESS space mission revealed five rare roAp stars, including the fastest pulsator in this class.

Artist's impression of a rapidly oscillating Ap star (roAp), highlighting its complexity.
The diversity of physical phenomena taking place in their outer layers, makes roAp
stars ideal test beds to the modelling of stellar physics. Credit: Victoria Antoci
(Stellar Astrophysics Centre, Aarhus University)

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Using asteroseismic techniques, an international team searched for pulsations in a subsample of five thousand stars, from the 32 thousand observed in short cadence in the first two sectors (roughly the first two months of science operations) of NASA‘s Transiting Exoplanet Survey Satellite (TESS), and found five rare rapidly oscillating Ap (roAp) stars. ...

Among the stellar data, the team found the fastest known roAp pulsator, which completes one pulsation every 4.7 minutes. Two of these five stars were found to be particularly challenging to the currently understanding of the field, one because it is cooler than theoretically expected for a roAp star and the other because it exhibits pulsation frequencies that are unexpectedly high. ...

Following an in-depth analysis of 80 stars previously known to be chemically peculiar, the team also found 27 new rotational Ap variables, and derived their rotation periods, based on brightness changes during the star’s rotation, produced by passing chemical spots. ...

For seven roAp stars, previously known from ground-based observations, high-precision photometric data was also gathered. For four of these stars, it was possible to set constraints on the star’s inclination angle and magnetic obliquity. ...

Rotation and Pulsation in Ap Stars: First Light Results from TESS Sectors 1 and 2 ~ M.S. Cunha et al

• Monthly Notices of the RAS (online 07 Jun 2019) DOI: 10.1093/mnras/stz1332
• arXiv.org > astro-ph > arXiv:1906.01111 > 03 Jun 2019

[neufer]

<<Przybylski's Star, or HD 101065, is a peculiar star that is located about 410 light years from the Sun in the constellation Centaurus. In 1961, the Polish-Australian astronomer Antoni Przybylski discovered that this star had a peculiar spectrum that would not fit into the standard framework for stellar classification. Przybylski's observations indicated unusually low amounts of iron and nickel in the star's spectrum, but higher amounts of unusual elements like strontium, niobium, scandium, yttrium, caesium, neodymium, praseodymium, thorium, ytterbium, and uranium. In fact, at first Przybylski doubted that iron was present in the spectrum at all. Modern work shows that the iron-group elements are somewhat below normal in abundance, but it's clear that the lanthanoids and other exotic elements are highly overabundant. As a result of these peculiar abundances this star belongs firmly in the Ap star class. [In fact,] HD 101065 is the prototype star of the roAp star class. It was discovered to pulsate photometrically in 1978 with a period of 12.15 min.

According to the Encyclopedia of Astrobiology, Astronomy, and Spaceflight, Przybylski's Star is…

• "One of the most chemically peculiar stars known; it is named informally after its discoverer, the Polish-Australian astronomer, Antoni Przybylski.… Apart from the usual lines of hydrogen and the calcium H and K, the strongest lines in HD 101065 are due to singly ionized lanthanides, presenting a spectrum similar to that of an S star, a highly evolved object whose atmosphere is enriched with recently synthesized material from deep within its interior. Yet, in other respects, HD 101065 appears to be a main sequence star or subgiant. One possibility is that it is a cool, extreme Ap star, a theory supported by the discovery of a several kilogauss magnetic field in HD 101065 similar to that of many other Ap stars. The outstanding difficulty with HD 101065 as an Ap star was that its spectrum didn't look like the others. Lines of neutral and first ionized iron are prominent in the spectra of Ap stars, and in some cases, the iron is clearly overabundant.">>

Przybylski's Star also contains many different short-lived actinide elements with actinium, protactinium, neptunium, plutonium, americium, curium, berkelium, californium, and einsteinium being detected. Other radioactive elements discovered in this star include technetium and promethium. Because of the odd properties of this star, there are numerous theories about why the oddities occur. The most interesting of them is that the star contains some long-lived nuclides from the island of stability (e.g. ²⁹⁸Fl, ³⁰⁴120, or ³¹⁰126) and that the observed short-lived actinides are the daughters of these progenitors, occurring in secular equilibrium with their parents.>>

[BDanielMayfield]

<<Przybylski's Star, or HD 101065, is a peculiar star that is located about 410 light years from the Sun in the constellation Centaurus. In 1961, the Polish-Australian astronomer Antoni Przybylski discovered that this star had a peculiar spectrum that would not fit into the standard framework for stellar classification. Przybylski's observations indicated unusually low amounts of iron and nickel in the star's spectrum, but higher amounts of unusual elements like strontium, niobium, scandium, yttrium, caesium, neodymium, praseodymium, thorium, ytterbium, and uranium. In fact, at first Przybylski doubted that iron was present in the spectrum at all. Modern work shows that the iron-group elements are somewhat below normal in abundance, but it's clear that the lanthanoids and other exotic elements are highly overabundant. As a result of these peculiar abundances this star belongs firmly in the Ap star class. [In fact,] HD 101065 is the prototype star of the roAp star class. It was discovered to pulsate photometrically in 1978 with a period of 12.15 min.

According to the Encyclopedia of Astrobiology, Astronomy, and Spaceflight, Przybylski's Star is…

• "One of the most chemically peculiar stars known; it is named informally after its discoverer, the Polish-Australian astronomer, Antoni Przybylski.… Apart from the usual lines of hydrogen and the calcium H and K, the strongest lines in HD 101065 are due to singly ionized lanthanides, presenting a spectrum similar to that of an S star, a highly evolved object whose atmosphere is enriched with recently synthesized material from deep within its interior. Yet, in other respects, HD 101065 appears to be a main sequence star or subgiant. One possibility is that it is a cool, extreme Ap star, a theory supported by the discovery of a several kilogauss magnetic field in HD 101065 similar to that of many other Ap stars. The outstanding difficulty with HD 101065 as an Ap star was that its spectrum didn't look like the others. Lines of neutral and first ionized iron are prominent in the spectra of Ap stars, and in some cases, the iron is clearly overabundant.">>

Przybylski's Star also contains many different short-lived actinide elements with actinium, protactinium, neptunium, plutonium, americium, curium, berkelium, californium, and einsteinium being detected. Other radioactive elements discovered in this star include technetium and promethium. Because of the odd properties of this star, there are numerous theories about why the oddities occur. The most interesting of them is that the star contains some long-lived nuclides from the island of stability (e.g. ²⁹⁸Fl, ³⁰⁴120, or ³¹⁰126) and that the observed short-lived actinides are the daughters of these progenitors, occurring in secular equilibrium with their parents.>>

Thank you for bringing this most fascinating star to our attention Art.

Guesses as to its very strange r-process element mix. Either: (1) The star had a close encounter with a kilo-nova blast from a merger of two neutron stars. Or (2) The star has some rare natural way to accelerate and collide heavy neutron rich nuclei with enough energy to fuse these ultra heavy elements and then dredge this production up to its surface.

But however these heretofore impossible [or nearly impossible] to create on Earth elements are forged, this star is indicating that an "island of stability" further up the periodic table very likely does exist

Bruce

[bystander]

TESS Finds Its Smallest Planet Yet
NASA | GSFC | TESS | 2019 Jun 27

Click to play embedded YouTube video.

TESS Discovers Its Tiniest World To Date
Credit: NASA/GSFC/SVS, C.Smith (USRA), J. Kazmierczak (UMCP)
Music: "Autumn Rush" from Killer Tracks

NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered a world between the sizes of Mars and Earth orbiting a bright, cool, nearby star. The planet, called L 98-59b, marks the tiniest discovered by TESS to date.

Two other worlds orbit the same star. While all three planets’ sizes are known, further study with other telescopes will be needed to determine if they have atmospheres and, if so, which gases are present. The L 98-59 worlds nearly double the number of small exoplanets — that is, planets beyond our solar system — that have the best potential for this kind of follow-up. ...

L 98-59b is around 80% Earth’s size and about 10% smaller than the previous record holder discovered by TESS. Its host star, L 98-59, is an M dwarf about one-third the mass of the Sun and lies about 35 light-years away in the southern constellation Volans. While L 98-59b is a record for TESS, even smaller planets have been discovered in data collected by NASA’s Kepler satellite, including Kepler-37b, which is only 20% larger than the Moon.

The two other worlds in the system, L 98-59c and L 98-59d, are respectively around 1.4 and 1.6 times Earth’s size. All three were discovered by TESS using transits, periodic dips in the star’s brightness caused when each planet passes in front of it. ...

The L 98-59 System: Three Transiting, Terrestrial-size Planets Orbiting a Nearby M Dwarf ~ Veselin B. Kostov et al

• Astronomical Journal 158(1):32 (2019 July) DOI: 10.3847/1538-3881/ab2459
• arXiv.org > astro-ph > arXiv:1903.08017 > 19 Mar 2019 (v1), 28 May 2019 (v2)