1 / 15

PASS – a Permanent All Sky Survey for the Detection of Transiting Planets

PASS – a Permanent All Sky Survey for the Detection of Transiting Planets. Hans J. Deeg 1 , Roi Alonso 1 , Juan Antonio Belmonte 1 , Khalid Alsubai 2 , Laurance Doyle 3 1 Instituto de Astrofísica de Canarias, Spain , 2 Univ of St Andrews, Great Britain, 3 SETI Institute, USA .

akiko
Download Presentation

PASS – a Permanent All Sky Survey for the Detection of Transiting Planets

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. PASS – a Permanent All Sky Survey for the Detection of Transiting Planets Hans J. Deeg1, Roi Alonso1, Juan Antonio Belmonte1, Khalid Alsubai2, Laurance Doyle3 1Instituto de Astrofísica de Canarias, Spain, 2Univ of St Andrews, Great Britain, 3SETI Institute, USA • an instrument capable to perform a permanent photometric survey of the entire (visible) sky • principal objective: detection of all giant planets that are transiting bright stars • many additional objectives can be realized • -Detection/study of variable phenomena of all kinds • prototype of PASS at Obs. Teide, Tenerife • possiblities for collaborations - placement on Dome C ?

  2. Main-Objective of PASS: • Detection of giant planet transits of all stars, with a magnitude limit of V ~ 10.5. • Surveying about 150 000 stars in one hemisphere, 250 000 in entire sky • ~60 planets may be detected in one hemisphere, 100 in total. • This will give the best sample of planets for follow-up studies: • detects star-planet systems with highest brightness (=signal), typically nearby ones. • follow-up measurements need highest possible S/N for scientific advances (i.e. spectroscopy of atmosphere, multi-color photometry) . • transiting planets detected by PASS will provide an optimum sample for a variety of research (using larger ground based or space based instruments) to gain a deeper insight into the formation and current physical status of giant planets and their atmospheres.

  3. The Instrument N E W horizon dashed line: 30°alt S Local Sky view28.5°N • current working hypothesis: • 15 cameras on fixed mount • f=50mm, 1k x 1k or 2k x 2k CCDs • 28°x28° field of view (50 or 100”/pix) • complete coverage for altitudes > 34° • coverage  > –17.5° from Tenerife • full sky coverage with 2nd instrument in South

  4. PASS would perform real-time all-sky observations for transit detection. The context of other experiments: planet transit detection experiments telescopes with guiding: surveying small zones in sky real-time all-sky-observations PASS fish-eye lenses: for meterological surveys, observing site quality, meteorite detection

  5. long-term follow-up of eclipsing binary minimum times is another method to detect planets Anxilliary Objectives of PASS: • Detection of any temporal astronomical phenomena: • Detection and follow-up of stellar variabilities with low amplitudes (up to 0.1%, depending on stellar brightness and frequency) • -variable stars of any kind • -flares • Detection of supernovae • Recording of frequency and direction of meteorites • Detection of optical counterparts to gamma ray bursts and ‘optical flashes’ • Detection of asteroids, comets, stellar occultations (e.g. by Kuiper-belt objects) • Sky-quality and meteorological statistics: • Recording of sky brightness and extinction in all directions • Percentage of clear sky, clouds • Detection of satellites and airplanes (intrusions into protected sky area over observatory)

  6. N 1m The PASS Instrument • Working hypothesis: • 15 Cameras on a common fixed mount. • f=50mm lenses, 28°x28°f.o.v. • CCD detectors with about 25x25mm size (1k x 1k CCD: scale of 100”/pix.) • Features: • permanent survey of entire visible sky is only possible with a fixed instrumment • mechanical simplicity, low maintenance • Stars will trail over exactly the same pixels every night at the same sidereal time: • no guiding or flatfielding errors, high stability and repeatability. • brightness-behaviour of each star can be compared across many nights and against many other stars. • Long duration of observations allows calibration for different meteorological conditions (eg. extinction, temperature). Seeing is not important. drawn with 10 cameras only

  7. Yearly observational coverage (instruments in N and S) Assumptions: -one site at 30ºN -one site at 35ºS - complete sky above 30º altitude is observed -1500 hrs/yr of clear sky blue line: coverage from N violet line: coverage from S green line: summed coverage (night-hours may not overlap in N and S) with sites in Europe and (Chile or Australia, Antarctica): -> fairly uniform coverage over entire declination range Expected number of hours that a star at a given declination can be observed in one year

  8. Dome C yearly observational coverage Assumptions: -one site at 30ºN -Dome C at 75ºS - complete sky above 15º in Dome C -2000 hrs/yr in Dome C -1500 hrs/yr in N blue line: coverage from N violet line: coverage from S green line: summed coverage Expected number of hours that a star at a given declination can be observed in one year

  9. Approach of feasability study financed by Span. Plan Nacional Astronomía y Astrofísica Theoretical S/N calculations Photometry on artificial images with all known noise characteristics Photometry on real images under controlled conditions agrees well TBD

  10. S/N from photometry on simulated images, texp=20s PASS - Baseline : CCD KAF1001 (1k x1k) 50mm, f/2.0, texp=20sec, obsv. site: alt=2400m, no moon, 1.4 airmass S/N calculations Curve is Total S/N in 20 sec from left gaph 90 x90 pix, 2.5° x 2.5° 10° gal. lat. Limit for transit detc: rms ~3.5mmag in 900sec

  11. The PASS prototype • Started this year with funding by Span. Science Ministry. (Pl. Nac. AYA-2002-04566 ) • - 1-2 cameras; currently a loaned AP10, 2k x 2k Thomson CCD, further one will be obtained soon. • - lenses Nikon 50mm/1.2, 50/1.4 • - fixed mount with adjustable tripode head. • Sequences of a few hours have beentaken, analysis in progress • Construction of dome in progress • Potential placement at DomeC • no moving part with Kodak KAI series interline CCD ‘First light’ 16 Jan 04 with AP10 (2k x2k) camera loaned by Univ. St.Andrews (K. Horne)

  12. Objectives of PASS prototype • get observational data for feasibility study of PASS concept • detailed characterization of instrument in its capability to detect planets (’discovery space’) • development of photometry software • comparison with simulated data • study about possible additional objectives • define specifications for a final instrument • start of planet survey with 2–camera system

  13. PASS0 image texp=60sec, f/2.0 (f=50mm) stars to ~11 mag can be identified visually seq. of 20 sec exposures taken in first night

  14. Collaborations are seeked... • real time pipeline processing among several computers • everything related with databases • definition of stellar sample (all-sky study on MS fraction; stellar types) • classification / interpretation of variables’ lightcurves • any kind of study towards definition of auxiliary objectives • follow-up/verification observations of candidates (transits and variables/aux. objectives)

  15. Conclusions • An instrument with a novel design for planetary transit detection is being developed • Primary goal is detection of ALL giant-planet transits around bright (nearby) stars • Ample range of auxilliary objectives • Realization of these objectives needs a variety of expertise and development of analysis modules, opportunities for participation • Observations with prototypes 2004-05: -detailed characterization of instrument capabilities -verification of achievability of objectives (‘detection-space’) will result • Interested in collaborations • more info in www.iac.es/proyectos/pass; paper accepted for PASP

More Related