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Recent Results from the Kepler Mission Ron Gilliland - STScI - 9 June 2010.

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Presentation on theme: "Recent Results from the Kepler Mission Ron Gilliland - STScI - 9 June 2010."— Presentation transcript:

1 Recent Results from the Kepler Mission Ron Gilliland - STScI - 9 June 2010

2 Mission Goal, Outline and Science Team Acknowledgements 1. Mission profile -- field and stars observed, data acquired. 2. Asteroseismology. Context, Solar-like stars, red giants. 3. Other Astrophysics. Orbiting White Dwarfs, Doppler Boosting, and Microlensing. Co-investigators: Bill Borucki (SPI), Dave Koch (DSPI, retired), Natalie Batalha (DSPI), Gibor Basri, Tim Brown, Doug Caldwell, Jørgen Christensen-Dalsgaard, Bill Cochran, Edna DeVore, Ted Dunham, John Geary, Nick Gautier, Ron Gilliland, Alan Gould, Jon Jenkins, Yoji Kondo, Dave Latham, Jack Lissauer, Geoff Marcy, Dave Monet, & Dimitar Sasselov. Science Working Group: Alan Boss, John Caldwell, Andrea Dupree, Steve Howell, Hans Kjeldsen, Søren Meibom, David Morrison, & Jill Tarter. Participating Scientists: Derek Buzasi, Dave Charbonneau, Laurance Doyle, Eric Ford, Jonathan Fortney, Matt Holman, Sara Seager, Jason Steffen, & Bill Welsh. Significant others: Jason Rowe, Lars Buchhave, Howard Isaacson, Michael Endl, Phillip MacQueen, Debra Fischer, Guillermo Torres, Steve Bryson, Mike Haas, Jessie Dotson. Kepler’s five year mission is to go where no mission has gone before and discover strange new worlds like our own orbiting distant stars.

3 The Kepler focal plane projection Module at top center lost 9 months into mission. Same field is viewed throughout mission, essentially forming a 3.5 yr movie with 30 minute frame interval for 150,000 stars, 1 minute for 512.

4 Pixels to Time Series We only keep ~5% of pixels -- ‘postage-stamps’ on stars. Prime technical driver is high duty cycle, high Signal to Noise. FOV here is 1x1 degree.

5 l =2, n = 20 mode

6

7 Asteroseismology of a solar-like Star. From Time Series to Asteroseismology Inferences -- HAT-P-7 Based on Christensen-Dalsgaard et al. 2010, ApJL. Time domain processing this page. 1: Aperture Photometry data from SOC.2: Detrend, fit transit, then subtract. 3: Time series ready for asteroseismology.

8 From Time Series to Asteroseismology Inferences -- HAT-P-7 Based on Christensen-Dalsgaard et al. 2010, ApJ, 713, L164. Frequency domain and inferences. A mean stellar density of 0.271 +/- 0.003 g/cm^3 results. A fit of the stellar density, Teff and [Fe/H] are then made to Yonsei-Yale evolutionary tracks arriving at (using Brown ApJ 2010 approach): R = 1.991 +/- 0.018 solar M = 1.520 +/- 0.036 solar age = 2.14 +/- 0.26 Gyr

9 More Solar-like stars. Three 9th magnitude G V-IV stars with clear oscillations. By design these all have Teff within ~100 K of solar. Each has an estimated mass of 1.05 to 1.1 solar with 0.1 errors. From the top gravities range over: 4.56, 4.32, 3.84 with corresponding radii of 1.18, 1.31 and 2.1 solar. ---------------------------------- Kepler has now provided 100s of detections of this quality, theoretical interpretation is well underway, but a large task. Chaplin et al. 2010, ApJL.

10 Oscillations in Red Giants. Bedding, et al. 2010, ApJL. Figure to right shows progression of peak power in oscillations for large red giants at the top at ~15 micro- Hz to small red giants at the bottom near 240 micro- Hz. Oscillations are now being analyzed in detail for ~2,000 red giants allowing study of physical properties over RGB. PR version of Stello et al. 2010, ApJl.

11 Other Astrophysics -- Eclipsing White Dwarfs. Rowe et al. 2010 ApJL -- discovery paper of KOI-74 interpreted as 9400 K host A star with 5.2 day orbiting WD of 13000 K, M =.02-.11, R =.04 solar. New interpretation by van Kerkwijk et al, 2010 ApJ invoking Doppler Boosting arrives at 0.22 solar mass for secondary (Maxted et al 2000 possible detection). DiStefano arXiv: 1002.3009 predicts order 500 orbiting WDs, neutron stars, etc will be detected by Kepler, often relying on microlensing (Sahu & Gilliland, 2003, ApJ). Doppler beaming predicted by Loeb and Gaudi, 2003, ApJ (in Kepler context). delta mag =

12 Kepler’s view of KPD 1946+4340, a relativistic binary star. Steven Bloemen, et al. 2010, sub. Inferred system is a sub-dwarf B star in a shell He burning star with a Teff of 35000 K, mass 0.47, and radius 0.2 solar, orbited by a 16000 K, mass 0.59, radius 0.01 solar White Dwarf. The orbital period is 0.4 days. ------------------- Here a very strong Doppler beaming effect is clearly present at the 0.1% level. This is the first time near-field gravitational lensing has been made use of to my knowledge. Star is at V = 14.28.

13 Summary and Look Forward. Kepler is now at end of year 1 of 3.5, hope for 2.5 year extension. Planet detection and validation is in full swing -- challenging work remains, especially in area of confirming terrestrial candidates, and in assessing matters of completeness and selection effects. More announcements next week. Asteroseismology is producing spectacular results, field will be enriched with orders of magnitude more targets with good solutions. Astrophysical effects such as Doppler boosting, and near-field microlensing are being seen for the first time. First 45 days of data become public on June 15 for 99.5% of targets, the other 0.5% are KOIs to be released February 2011. Cycle 2 of GO program starts ~ June 20th with 36 proposals approved on wide range of science topics.


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