Author Topic: NASA - Transiting Exoplanet Survey Satellite ( TESS ) updates  (Read 73295 times)

Offline Dao Angkan

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NASA Exoplanet Hunter Racks Up Bizarre Worlds and Exploding Stars

Other highlights from that article:

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TESS works better than team members had dared to dream, says George Ricker, a physicist at MIT and the mission’s principal investigator. Its four cameras can see objects 20% fainter, and focus more sharply, than originally expected. [...]

His team is now writing a proposal to NASA asking that TESS’s mission be extended past its initial two years. That deadline for the proposal was 1 February—but the ongoing partial US government shutdown means Ricker isn’t sure how that timing could change.

TESS is guaranteed to be extended, the interesting thing will be which observation plan they settle on for the extended mission. Personally I'd like them to extend the time on the current sectors ... they could extend the ~1 year observing of the Northern hemisphere to ~2 years, thus finding longer distance planets. I think it's more likely that they'll target the galactic plane which is currently missed by the initial survey.
« Last Edit: 01/09/2019 09:35 pm by Dao Angkan »

Offline Alpha_Centauri

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George Ricker mentioned in the press conference that their current plans are to cover part of the ecliptic plane in the next extension.  Unfortunately part of the ecliptic will not be visible until further mission extensions as the Earth will be in the way.

Ultimately the highest value targets are rocky planets in the habitable zone. Since TESS is only sensitive to rocky planets orbiting M dwarfs, which have short-period habitable zones, it makes sense to view more regions of the sky and collect more JWST targets than extend the time baseline right now.

Offline Dao Angkan

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Ooops ... I said galactic plane, but meant ecliptic plane as "Alpha_Centauri" mentioned.

And yes, TESS wants to find rocky planets, but if it could find larger planets further out, then chances are that smaller planets further in would have similar inclinations and could be potentially found by follow-up transit surveys. Still ... TESS should last for a few decades, so should eventually do many follow-on extended missions.

Offline jebbo

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It should find some larger planets in longer period orbits by "lucky transits" where we see a single transit only.  Assuming we can see the ingress and egress slopes, this should give a reasonable guess at period.

--- Tony

Offline Star One

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NASA - Transiting Exoplanet Survey Satellite ( TESS ) updates
« Reply #164 on: 01/10/2019 12:01 pm »
It moves on from an observation after 27 days, can this period be altered so that it stares at a patch of sky for longer periods?
« Last Edit: 01/10/2019 12:01 pm by Star One »

Offline ncb1397

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It moves on from an observation after 27 days, can this period be altered so that it stares at a patch of sky for longer periods?

There is overlap for longer than 27 days in certain zones (up to a year). Anyways, haven't seen this NASA article posted:


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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.



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Next is LHS 3884b, 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.

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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). “This planet has a greater density than Neptune, but it isn’t rocky. It could be a water planet or have some other type of substantial atmosphere,” explained Diana Dragomir, a Hubble Fellow at MKI and lead author of a paper describing the find. 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.
https://exoplanets.nasa.gov/news/1542/nasas-tess-rounds-up-its-first-planets-snares-far-flung-supernovae/
« Last Edit: 01/10/2019 12:39 pm by ncb1397 »

Offline Hungry4info3

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Five low-mass planet candidates orbiting TYC 8856-192-1 (TOI-125), two of which have been confirmed.
https://arxiv.org/abs/1901.09092

Offline Hungry4info3

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An Eccentric Massive Jupiter Orbiting a Sub-Giant on a 9.5 Day Period Discovered in the Transiting Exoplanet Survey Satellite Full Frame Images
https://arxiv.org/abs/1901.09950

TOI-172 = TYC 6932-301-1

Offline Star One

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NASA - Transiting Exoplanet Survey Satellite ( TESS ) updates
« Reply #168 on: 02/13/2019 06:22 am »
We found two new exoplanets! (using TESS) - Cool Worlds

« Last Edit: 02/13/2019 06:22 am by Star One »

Offline Star One

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An Exoplanet With an 11-Hour Orbit
Friday, February 1, 2019
Science Update - A look at CfA discoveries from recent journals
The Transiting Exoplanet Survey Satellite (TESS) was launched on April 18 of last year with the primary objective of discovering transiting planets smaller than Neptune around stars bright enough for spectroscopic investigations of their masses and atmospheres. Before TESS there were roughly 385 exoplanets known with masses smaller than Neptune, with orbital periods ranging from less than half-a-day to about two Earth-years.

CfA astronomers Dave Latham, Samuel Quinn, Dave Charbonneau, Jonathan Irwin, Kristo Ment, Jennifer Winters, Martin Paegert, Dimitar Sasselov, and Willie Torres and a large team of TESS collaborators report that TESS has found a "hot Earth" exoplanet, rocky in composition, only about fifty light-years away and orbiting its dwarf star in a mere eleven hours. The planet has a radius of about 1.3 Earth-radii, enough to host an atmosphere, but its short orbital period means it lies very close to its star – only about seven stellar radii. The inferred surface temperature is about 800 kelvin, rather hot to be able to retain an atmosphere but possible. The scientists note, however, that if the planet had formed in roughly this close-in location, its atmosphere would likely have been stripped away in the star’s youth when it was more luminous and had more intense chromospheric activity. In any case, the planet's proximity to us offers the opportunity of characterizing any atmosphere it might have using transit and occultation spectra of the source and the result, interesting in its own right, would also shed light on the planet's formation.


Offline Star One

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The hunt is on for closest Earth-like planets

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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,” published March 26 in Astrophysical Journal Letters. Lead author Lisa Kaltenegger, professor of astronomy in the College of Arts and Sciences and director of Cornell’s Carl Sagan Institute, is a member of the TESS science team.

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.


Offline Star One

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TESS Delivers Its First Earth-sized Planet and a Warm Sub-Neptune*

The future of exoplanet science is bright, as Transiting Exoplanet Survey Satellite (TESS) once again demonstrates with the discovery of its longest-period confirmed planet to date. We hereby present HD 21749b (TOI 186.01), a sub-Neptune in a 36 day orbit around a bright (V = 8.1) nearby (16 pc) K4.5 dwarf. TESS measures HD 21749b to be ${2.61}_{-0.16}^{+0.17}$ R ⊕, and combined archival and follow-up precision radial velocity data put the mass of the planet at ${22.7}_{-1.9}^{+2.2}$ M ⊕. HD 21749b contributes to the TESS Level 1 Science Requirement of providing 50 transiting planets smaller than 4 R ⊕ with measured masses. Furthermore, we report the discovery of HD 21749c (TOI 186.02), the first Earth-sized (${R}_{p}={0.892}_{-0.058}^{+0.064}{R}_{\oplus }$) planet from TESS. The HD 21749 system is a prime target for comparative studies of planetary composition and architecture in multi-planet systems.

Offline Hungry4info3

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Worth noting that this is the same system reported by Trifonov, et al. as GJ 143, though they weren't able to confirm the planetary nature of the ~Earth-mass planet (Discussed on this forum here).
« Last Edit: 04/15/2019 11:35 pm by Hungry4info3 »

Offline Star One

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Three exocomets discovered around the star Beta Pictoris

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Three extrasolar comets have been discovered around the star Beta Pictoris, 63 light years away, by an international team including a University of Warwick researcher.

Analysis of data from the current NASA mission TESS has revealed the objects for the first time thanks to Sebastian Zieba and Konstanze Zwintz from the Institute of Astro- and Particle Physics at the University of Innsbruck, together with colleagues from Leiden University (Netherlands) and the University of Warwick (UK).

Here’s the related paper.

https://arxiv.org/abs/1903.11071v1

Offline speedevil

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Dr. Jeff Volosin - TESS - 21st Annual International Mars Society Convention
@17:20 'You can see the rise of a supernova and you can see it tail off. Not to get ahead of ourselves, but we're publishing in the next couple of weeks something around that' - paraphrased.
Just after that he refers again to 'usually you don't have the benefit of a camera which takes data every two seconds' - which is odd for a comment about supernova if there is no triggering on high brightness events, because if there is no fast trigger, then there is no point at all, because by the time the data is downlinked, the next opportunity to observe that spot will often be a couple of years hence, and the only frames stored would be at the low 'full frame' decimated rate.

If you have ten prior frames stored, and have enough spare CPU to threshold every few frames to see if anything has popped up five sigma and add it to a list of areas to store postage stamps around that area at 0.5s  until it quiets down.

Will be interesting to see details in the paper referred to.

I have just looked, and found no mention on arxiv of any supernova detections with TESS that were not done using full-frame images at 30minute cadences. (searching on TESS supernova)
I am unsure what the above phrasing was referring to about 'two seconds' in the context of publication.
In principle, TESS could have regions uploaded to it to watch following a ground detection. This does not appear to have been done.

Offline jg

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I will be meeting with the TESS group next week, if anyone has a particularly burning question for them...

I have an agenda of my own, of course, so don't expect me to ask more than a few quick questions...

                                           - Jim

Offline speedevil

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I will be meeting with the TESS group next week, if anyone has a particularly burning question for them...

I have an agenda of my own, of course, so don't expect me to ask more than a few quick questions...

As implied by the above posts 'What would change if you weren't limited by DSN bandwidth' ?

Offline theinternetftw

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I will be meeting with the TESS group next week, if anyone has a particularly burning question for them...

Have they narrowed down what regimes they'd prefer for an extended mission?

Offline PahTo

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How do we better resolve inner system rocky worlds?  Resolve includes atmospheric composition.

Offline speedevil

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How do we better resolve inner system rocky worlds?  Resolve includes atmospheric composition.

TESS is not going to be able to meaningfully contribute to atmospheric composition in more than a very rough way.
It will be able to nail down reasonably transit shape and depth for many inner system rocky planets, letting us get a good idea of if they are rocky or not, when combined with their mass.

But it has no spectroscope to measure atmospheric absorbtion or occulting system to block out the star to see the planets light.
Even if it did have an occulting system to block the star, it is not sensitive enough to see the planets light. (for other than very close in hot Jupiters)

Spectroscopic followup by ground-based telescopes (or space based, though that is a more limited resource) is needed to get to our current limits.
We need better spectrometers, and more sensitive telescopes in orbit in order to be able to really block well the light from the primary and properly characterise the planets residual atmosphere and surface.

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