The Completeness of Planetary Searches

Adric R. Riedel2009 04 13

Why?

Image Credit: NASA/JPL (Galileo)

• Extrasolar planets may be the future of humanity

• Since 1995, hundreds of planets have been found orbiting sunlike stars.

The Question:

If humanity leaves the Earth, where will we go?

Where are we looking?Where are we NOT looking?

The Dædalus Project

An unmanned interstellar spacecraft designed to reach Barnard’s Star within a human lifetime

– Using only technologies expected to be available within the near future (nuclear explosion-based propulsion)

– Would visit the supposed planets

Time to Barnard’s Star: 50 years (0.12c)

http://www.daviddarling.info/encyclopedia/D/Daedalus.html

http://www.daviddarling.info/images/Daedalus3.jpg

The Project

How many stars within 25 parsecs (81.5 light years, 680 years at 0.12c) are being looked at for planets?

This requires:– A list of stars within 25 parsecs– A list of stars being looked at for planets

The 25 parsec sample

The NStars database (Backman et al. 2000)

2644 objects (including planets and brown dwarfs) in 2037 systems

Expectation is 6000 systems…

The 25 parsec map

The 25 parsec sample

Spectral types generated from absolute V magnitudes

– Less than half the objects in NStars have known spectral types or photometric color information

– Not all stars within 25 parsecs (or in NStars) are on the main sequence

All systems (including ones with known types) were assigned types this way. It’s consistently bogus.

Summing it all up: 25 parsec list

Planet Searches listPlanet search teams are not required to publish a list of their intended targetsFortunately, some of them have.All data is from VizieR, except for a paper by van de Kamp (thanks to Andreas Güth for translating it from German)

Please note: All lists are fragmentary

Planet Searches listCalifornia Planet Search (Doppler)

–Lick-Carnegie–UC-NASA Eta Earth

Geneva Planet Search (Doppler)

–CORALIE–ELODIE–HARPS

Okayama/HIDES (Doppler)Walker (Doppler)Van de Kamp (Astrometry)OGLE-I (Microlensing)

CoRoT (Transit)

UNSW (Transit)

PISCES (Transit)

WASP0 (Transit)

EXPLORE (Transit)

EPOCh (Transit)

HATnet (Transit)

TReS (Transit)

Exoplanet.eu knowns list

Exoplanet.eu retracted list

The map of planet searches

Summing it all up: Planet Searches

The map of planet searches

Where are we (not) looking?

Remember: These are only what is published.

Works Cited

The list of planet searches

California Planet Search (CPS) (Doppler)– Marcy, Butler, Fischer, Vogt– 881 probable targets from Nidever et al. 2002– Also run UC-NASA Eta Earth project, looking at the 230

nearest GKM stars

Geneva Planet Search (Doppler)– Mayor, Queloz, Udry– CORALIE, ELODIE, HARPS– 451 targets from HARPS (Sousa et al. 2008)

Okayama/HIDES (Doppler)– 57 targets from their first round (Takeda et al. 2005),

nothing since.

Gordon Walker (Doppler)– Unsuccessful 1980-1992 search of 21 stars despite looking

at Eps Eri– All but four targets are on the CPS list (Nidever et al. 2002)

The list of planet searches

van de Kamp (Astrometry)– 1940-1980s? Unsuccessful planetary search– 6 stars from van de Kamp (1983)– All but Stein 2051A are on the CPS list

OGLE (Microlensing)– 1992-1995 OGLE-I run– 177 stars from Udalski et al. (2005) catalog– OGLE is looking between us and the SMC and LMC

The list of planet searches

CoRoT (Transits)– Some overlap with Geneva Planet Search– Only publishes confirmed planetary transits– Data is 816 stars “within one of the exoplanet fields”

selected for radial velocity follow-up (Loillet et al. 2008)

UNSW (Transits)– University of New South Wales (Australia)– Data on 850 ‘astrophysically interesting variable stars’

(including planets) from their program. (Christiansen et al. 2008)

PISCES (Transits)– Planets In Stellar Clusters Extensive Survey– 102 stars from Mochejska et al. (2005)

WASP (Transits)– 75 stars from the WASP0 prototype (Kane et a. 2005,

catalog)

The list of planet searches

EXPLORE (Transits)– Promises a discussion of results from their first search

(EXPLORE I) where they searched 37,000 stars– Accompanying catalog is the exoplanet.eu list as of 18

July 2003

EPOCh (Transits)– Follow-up of already known transiting planets using the

Deep Impact spacecraft

HATnet (Transits)– Harvard-Smithsonian CFA, and overlap with CPS– Only publishes discoveries

TReS (Transits)– Completely missed this one.

The list of planet searches

To round out the list I include:– The www.exoplanets.eu known planets

list as of 27 March 2009 (344 stars)• Includes all systems from programs that

only publish planet results• 8 planets have no coordinates for the parent

star and were removed.

– The www.exoplanets.eu retracted planets list, from 27 March 2009 (57 stars)• 2 planets have no coordinates for the parent

star and were removed.