Transit Surveys
Abschätzung für unser Sonnensystem Planet Umlaufzeit Transitdauer ΔF Wahrscheinlichkeit [Jahr] [Stunde] [%] [%] Merkur 0.24 8.1 0.0012 1.19 Erde 1.00 13.0 0.0084 0.47 Jupiter 11.86 29.6 1.01 0.089 Neptun 164.8 71.3 0.127 0.015 Exoplanet 0.01-0.04 3-4 ~1 ~10 => Beobachtung vieler Sterne über einen längeren Zeitraum
This is where we have to be clever : N * : Detection probabilities To detect 1 transit N T we need to multiply the total number of detected stars in a target field, N stars, by: Things we can do nothing about : P g : Fraction of systems seen edge-on f: Fraction of stars with giant planets Something that just needs patience : P cov : N T = N stars P g f P cov N * coverage of a planet s orbit by observations Number of useful stars in the field-of-view with sufficient S/N depends on: instrument, observing conditions, photometry, field binary stars N * = N dwarf N S/N selection,
What Telescope to pick? FoV (the bigger the better) Magnitude range (go for the brightest?) Number of Stars (the more the merrier) Other factors: CCD high QE low noise Stable over long timescales Readout time Alignement working
Crouzet et al.
Kriterien zur Feldauswahl Wie kann man die Anzahl entdeckter Transitkandidaten maximieren? Beobachtungszeit (Feld möglichst lange sichtbar) Messgenauigkeit (Geringe Luftmasse) Anzahl der Sterne (Möglichst viele Sterne) Folie 6
Folie 7 Seminarvortrag > Thomas Fruth > 11.11.2010
Folie 8 Seminarvortrag > Thomas Fruth > 11.11.2010
Folie 9 Seminarvortrag > Thomas Fruth > 11.11.2010
Folie 10 Seminarvortrag > Thomas Fruth > 11.11.2010
Feldauswahl quantitativ Folie 11
Folie 12 Seminarvortrag > Thomas Fruth > 11.11.2010
The first planetary transits the search for transits of known extrasolar planets discovered by radial velocity the first transit observed the photometric search for transiting extrasolar planets the first planet detected by the method of transits arbonneau et al. 2000 ApJ, 529, L45 But planet was known before from radial velocity survey Udalski et al. 2002 AcA, 52, 115 confirmed by RV by Konacki et al. 2003 Nature, 421, L508
STARE (STellar Astrophysikcs & Research on Exoplanets) HD209458b: Umlaufzeit = 3.52 Tage Radius = 1.3 Jupiterradien Masse = 0.63 M Jupiter Dichte = 270-490 kg/m 3 (Charbonneau et al., 2000; Brown and Charbonneau 2000) STARE: Aperture Telescope FOV CCD Scale Filter Location 10 cm Schmidt Cassegrain 6 x 6 degree 2034x2034 pixel 10 arcsec/pixel Johnson R 1999-2000 Bolder since 2001 Tenerife
OGLE Chile 1.3m telescope 8 detectors (2kx4k) 35x35 arcminutes 0.26"/pixel 8 Planets detected 2002 2007 MV: 15-18 Depth: 0.5% - 2.2% Periods: 1.2 4.0 days http://ogle.astrouw.edu.pl/
TrES TrES: Trans-atlantic Exoplanet Survey (STARE is a member of the network) Three 10cm telescopes located at Lowell Observtory, Mount Palomar and the Canary Islands 5 Planets detected 2004-2011 MV: 11.4-13.7 Depth: 1% - 3% Periods: 1.3 3.5 days TrES-1b Alonso et al. 2004
XO Haleakala on Maui, Hawaii. twin 200mm Canon EF200 lenses at f/1.8. Apogee Ap8p CCD detectors (1024x1024) 24µm pixels. 7.2 square degrees 25.4"/pixel 5 Planets detected 2006 2008 MV: 9.8-12.1 Depth: 0.5% - 1.7% Periods: 2.6 4.2 days http://www.stsci.edu/~pmcc/xo/index.shtml
FLWO Arizona & Mauna Kea Six lenses (Takahashi) Apogee E10 detectors (2kx2k) 1.3x1.3 degrees per CCD 4.6"/pixel HATNet South: 2x4 lenses Since 2009 Australia / Chile 33 Planets detected 2006 2011 MV: 8.7-13.0 Depth: 0.43% - 2.18% Periods: 1.2 10.8 days HATNet https://www.cfa.harvard.edu/~gbakos/hat/index.html
La Palma & South Africa 2x 8 lenses (Canon 200mm f/1.8) e2v detectors (2kx2k) 7.8x7.8 degrees per CCD 13.7"/pixel 67 Planets detected 2006 2011 MV: 8.3-13.0 Depth: 0.6% - 2.4% Periods: 0.78 8.2 days SuperWASP http://www.superwasp.org/
CoRoT Space 27cm mirror system 4 detectors (2kx2k) 2.7x3.0 degrees 21 Planets detected 2007 2011 MV: 11.7-16.0 Depth: 0.04% - 2.6% Periods: 0.8 95 days http://smsc.cnes.fr/corot/index.htm
MEarth Arizona 8 40cm telescopes Apogee U42 detectors (2kx2k) 25x25 arcminutes 0.76"/pixel 1 Planets detected GJ1214b (2009) MV: 14.7 Depth: 1.6% Periods: 1.58 days https://www.cfa.harvard.edu/~zberta/mearth/
Kepler Space 1m mirror 42 detectors (2kx1k) 115 square degrees 13.7"/pixel 36 Planets detected (25+2+9) 2010 2011 MV: 11-15.0 Depth: 0.02% - 1.6% Periods: 0.8 118 days http://www.nasa.gov/mission_pages/kepler/main/index.html
Qatar New Mexico Four 400mm Canon f/2.8 One 200mm Canon f/2.0 FLI detectors (4kx4k) 5.2x5.2 degrees per CCD 4.6"/pixel 2 Planets detected 2010 2011 MV: 12.8-13.3 Depth: 2% - 3.7% Periods: 1.3 1.4 days http://www.qatarexoplanet.org/
Kepler & Qatar MEarth CoRoT XO, HATNet & SuperWASP TrES HD80606 OGLE STARE 185 transiting planets known, 695 planets in total
Transitsuche mit BEST II -- Feld 19 Thomas Fruth 14.11.2010
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BEST2 F19_043426 Transittiefe 4,7% Transitdauer 4,5h Periode 4,887d Einzelne Nächte Folie 27
Transitkandidaten in F19 Folie 28
F20 Folie 29
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ASTEP 400 40cm Newton telescope 2kx2k Andor CCD 1 square degree http://fizeau.unice.fr/astep/
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Concordia [France Italia] 75 06 S - 123 21 E 3233 m Concordia 1
TEST
Transits from ground and space (examples) HD209458b (V: 7.65 mag) 10cm aperture telescope from ground Hubble Space Telescope Charbonneau et al. 2000 detected by rv HD 209458 precision: 6x10-5 Brown et al. 2001 CoRoT-2b (V: 12.57 mag) 27cm aperture telescope in space 20cm aperture telescope at OHP detection Rauer et al. 2009 archive Alonso et al. 2009
Detection range of transit surveys GJ1214b GJ436b Groundbased surveys Kepler 19b CoRoT 7b Kepler 11 b-g Kepler 9d Kepler 10b Kepler 4b Space surveys
Transiting planets: HAT:red, WASP: turquoise, CoRoT: green, Kepler: yellow