NEAT - Nearby Earth Astrometric Telescope

From the exoplanet.eu mailing:

Nearby Earth Astrometric Telescope (NEAT) is a proposal for a space mission whose main objective is the detection and characterization of planetary systems around our closest “Sun-like” neighbors. NEAT main program will consist in observing ~200 nearest F, G and K stars, looking for planets like ours. For some of these stars, NEAT will even be able to detect planets smaller than the Earth.

NEAT has been submitted to ESA as an answer to the call for proposition for M-size space mission (M3) in its "Cosmic Vision 2015-2025" plan. It is based on a new concept using extremely-high precision astrometry. For more information, please visit the NEAT web site at http://neat.obs.ujf-grenoble.fr or contact one of the proposers.

Well estimated launch date is ~2020, so we won't be seeing much of this for a while. Nevertheless, astrometry has lots of advantages, so a dedicated mission certainly seems like a good idea (plus you can get a lot of info about binary stars along with it).

Gotta wonder how the unfortunate history of astrometric planet detection has influenced e.g. the cancellation of SIM-Lite though.

Hopefully the planet in HR 7162 will hold up under scrutiny.

High precision astrometry mission for the detection and characterization of nearby habitable planetary systems with the Nearby Earth Astrometric Telescope (NEAT)
http://arxiv.org/abs/1107.3643

Quote :

(abridged) A complete census of planetary systems around a volume-limited sample of solar-type stars (FGK dwarfs) in the Solar neighborhood with uniform sensitivity down to Earth-mass planets within their Habitable Zones out to several AUs would be a major milestone in extrasolar planets astrophysics. This fundamental goal can be achieved with a mission concept such as NEAT - the Nearby Earth Astrometric Telescope. NEAT is designed to carry out space-borne extremely-high-precision astrometric measurements sufficient to detect dynamical effects due to orbiting planets of mass even lower than Earth's around the nearest stars. Such a survey mission would provide the actual planetary masses and the full orbital geometry for all the components of the detected planetary systems down to the Earth-mass limit. The NEAT performance limits can be achieved by carrying out differential astrometry between the targets and a set of suitable reference stars in the field. The NEAT instrument design consists of an off-axis parabola single-mirror telescope, a detector with a large field of view made of small movable CCDs located around a fixed central CCD, and an interferometric calibration system originating from metrology fibers located at the primary mirror. The proposed mission architecture relies on the use of two satellites operating at L2 for 5 years, flying in formation and offering a capability of more than 20,000 reconfigurations (alternative option uses deployable boom). The NEAT primary science program will encompass an astrometric survey of our 200 closest F-, G- and K-type stellar neighbors, with an average of 50 visits. The remaining time might be allocated to improve the characterization of the architecture of selected planetary systems around nearby targets of specific interest (low-mass stars, young stars, etc.) discovered by Gaia, ground-based high-precision radial-velocity surveys.

anyone here could tell me Why MEAT discriminate M,L and T dwarf star? most of our nearby stars are M-dwarf,and would be interest get know the planets around the nearby M-dwarf stars and L,T dwarf planets...

Perhaps because of a lower signal-to-noise ratio inherent to dim stars. I don't know that much about the technology so it's just speculation on my part.

Looking for planets around L and T stars does not make sense.HZ there is so incredible close no life we look for can develop there

Well maybe looking for habitable planets around L and T dwarfs is a bit of a long shot (though such worlds have apparently had some theoretical consideration).

On the other hand looking for planets around such objects is probably not such a silly idea, probably will yield interesting scientific results especially since we aren't entirely sure how the majority of brown dwarfs are actually formed...

tommi59 wrote:

Looking for planets around L and T stars does not make sense.HZ there is so incredible close no life we look for can develop there

this a paper than talk about Brown Dwarf Planets and Habitability http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?2004IAUS..213..115A&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf

and here it's Centauri dreams article: http://www.centauri-dreams.org/?p=13058

Brown Dwarf could very well have habitable planets with resonance tidal heat with the brown dwarf other planets in the Brown Dwarf planetary system, like Io, Europa in the Jupiter moon system,or/and radioactive decay in planet core like in the earth core, that coud keep warm a planet ocean and developed life.

other thing brown dwarf planets,it's very interest planet formation astrophysics studies,and future interstellar travel.

NEAT, An Astrometric Telescope To Probe Planetary Systems Down To The Earth Mass Around Nearby Solar-Type Stars
http://arxiv.org/abs/1108.4784

Quote :

The NEAT (Nearby Earth Astrometric Telescope) mission is a proposition submitted to ESA for its 2010 call for M-size mission. The main scientific goal is to detect and characterize planetary systems in an exhaustive way down to 1 Earth mass in the habitable zone and further away, around nearby stars for F, G, and K spectral types. This survey would provide the actual planetary masses, the full characterization of the orbits including their inclination, for all the components of the planetary system down to that mass limit. Extremely- high-precision astrometry, in space, can detect the dynamical effect due to even low mass orbiting planets on their central star, reaching those scientific goals. NEAT will continue the work performed by Hipparcos (1mas precision) and Gaia (7{\mu}as aimed) by reaching a precision that is improved by two orders of magnitude (0.05{\mu}as, 1{\sigma} accuracy). The two modules of the payload, the telescope and the focal plane, must be placed 40m away leading to a formation flying option studied as the reference mission. NEAT will operate at L2 for 5 years, the telescope satellite moving around the focal plane one to point different targets and allowing whole sky coverage in less than 20 days. The payload is made of 3 subsystems: primary mirror and its dynamic support, the focal plane with the detectors, and the metrology. The principle is to measure the angles between the target star, usually bright (R \leq 6), and fainter reference stars (R \leq 11) using a metrology system that projects dynamical Young's fringes onto the focal plane. The proposed architecture relies on two satellites of about 700 kg, offering a capability of more than 20,000 reconfigurations. The two satellites are launched in a stacked configuration using a Soyuz ST launch, and are deployed after launch to individually perform cruise to their operational Lissajous orbit.

I'm personally becoming more and more convinced that astrometry is the way to go for discovering nearby planets, especially since it should be less affected by stellar activity which limits both RV and transits.

Given the loss of SIM-Lite, this one looks like it could be a very interesting mission.

At least ESA doesn't have the JWST funding black hole...

But, for the same cost, better launch a direct imaging mission to detect superearths or jovian planets, like the ESA proposed SEE COAST or other similar missions

A direct imaging mission would be the same cost as an astrometry mission? I'm highly skeptical of this. Do you have some numbers handy?

Well, the SEE COAST mission was proposed to ESA like an M class mission.

Obviously i' m thinking of a 1-3 meter telescope, not a TPF or Darwin class mission. This telescope can't find a truly earth HZ planet, but it could detect and characterize super earths and mature jovian planets. Better a direct detection of that kind of planets than an astrometric but not useful detection of an earth like planet.

I don' t remember well, but i think other teams had proposed NASA similar missions of coronographic telescopes 1-2 meters in diameter, with the budget of a discovery mission.

But NASA and ESA can do both missions (astrometric and spectroscopic lite) if they want.

Edit: For example the proposed TOPS mission to NASA.

arXiv:1207.6511v1: Malbet et al. (2012) "[astro-ph.IM]NEAT: a space born astrometric mission for the detection and characterization of nearby habitable planetary systems"

A review of future exoplanets mission:

http://www.thespacereview.com/article/2167/1

The article hints at a possible use of NEAT for followup of Kepler systems, like was planned for SIM, for a comprehensive characterization of planetary system architectures

Quote :

The main goal of the NEAT mission will be the detection of Earth analogs within 50 light-years. The NEAT duo will observe a list of 200 nearby Sun-like stars over several years. It will be able ascertain whether planets down to a mass of 1 Earth, or larger, orbit those stars. In addition, NEAT will be able to survey the solar systems discovered by Kepler, detecting giant planets that were missed by Kepler. These would be planets that did not transit their parent star during the Kepler mission, either because of the “wrong” orbital inclination or because their orbital period is too long. This will help to “fill in” the architecture of those solar systems, allowing a better understanding of how those systems are formed.

The team's engineers are pushing for a demostrative prototype, a micro-NEAT, to test the technologies involved. This protoype seems exciting by itself:

Quote :

the NEAT team is proposing a smallsat version based on PRISMA technology. This concept, micro-NEAT, would take the next step after NEAT-Pathfinder towards a full NEAT mission. Instead of 40 meters, the micro-NEAT duo would fly at a separation of 12 meters. This would limit the number of targets that would be observed, but it would still produce results on the prevalence of exoplanets around the nearest stars. The lower mass limit for exoplanets discovered by micro-NEAT would be 10 Earth masses for 25 of the nearest stars. However, it will be able to detect planets down to one Earth mass for the closest stellar twins, Alpha Centauri A and B. This demonstration of the capabilities of formation flying will set the stage for more ambitious astrometry missions.

Galzi wrote:

A review of future exoplanets mission:. The lower mass limit for exoplanets discovered by micro-NEAT would be 10 Earth masses for 25 of the nearest stars. However, it will be able to detect planets down to one Earth mass for the closest stellar twins, Alpha Centauri A and B. This demonstration of the capabilities of formation flying will set the stage for more ambitious astrometry missions.

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Interesting, it seems that the current discovery could significantly boost their chances of getting this proposal funded. It seems like the ideal mission at the current time.