Exoplanet Detection with an 8 LX200 : Part 1 : Preparation David Richards 2007-October All pictures in this presentation are by the author (unless specifically indicated) and were taken with 8 LX200 / ST7e The Aim Position Now Position Now UT Hours Flux (or Mag) Ingress Egress Mid Transit Light from Host Star Light from Control Star
Exoplanet Challenge First exoplanet transit detection made in HD b First exoplanet transit detection made in HD b HD (Osiris, 13 Pegasi ) Charbonneau et al 2000, Henry et al 2000 (from Hipparcos Images ?) HD (Osiris, 13 Pegasi ) Charbonneau et al 2000, Henry et al 2000 (from Hipparcos Images ?) Castellano et al (NASA Ames) demonstrated HD b transit detection with an 8 LX200 telescope and ST7e CCD camera Castellano et al (NASA Ames) demonstrated HD b transit detection with an 8 LX200 telescope and ST7e CCD camera JAAVSO, Vol 33, No 1, 2004 JAAVSO, Vol 33, No 1, 2004 Same equipment as me ! Same equipment as me ! Same journal volume as a paper by D.Mais and myself on Mira variables ! Same journal volume as a paper by D.Mais and myself on Mira variables ! Led to a strong ambition to detect an Exoplanet for myself Led to a strong ambition to detect an Exoplanet for myself 14 more transiting exoplanets discovered more transiting exoplanets discovered Its both feasible and now regularly proven that amateurs with CCD cameras and just moderately sized telescopes can detect transit events Its both feasible and now regularly proven that amateurs with CCD cameras and just moderately sized telescopes can detect transit events Ive made my own exoplanet detection attempts in 2005 and 2006, but without firm success Ive made my own exoplanet detection attempts in 2005 and 2006, but without firm success Requires ideal sky conditions and the highest possible precision (<0.005 m) Requires ideal sky conditions and the highest possible precision (<0.005 m) Im currently optimising my imaging setup and (with luck) hope to make a firm transit detection during the 2007/8 season. Im currently optimising my imaging setup and (with luck) hope to make a firm transit detection during the 2007/8 season.
Table of Nearby Transiting Exoplanets (Jul 2007) Note : Most known transiting exoplanet sols are visible from N. Hemisphere ) 5 distant exoplanets (OGLE-TR-10,56,111,113,132) in Sagittarius and Carina are not listed, [OGLE - Optical Gravitional Lensing Experiment ]
My Own Equipment & Setup Meade 8 LX200 Goto Telescope ST-7e CCD Camera Equatorial Wedge Permanent Pier
2005 Attempt – HD Planet HD b around HD (Osiris) Discovered in 1999 (followed up ) Parent Sol is a +7.6 magnitude star in Pegasus Orbital period 3.52 days. Transit duration ~ 3 hours, Transit depth mag Depth of magnitude dip being looked for 60s exp (C Filter) Attempted Transit Observation in V Filters, s exposures (V Filter)
2006 Attempt – TrES-1 End Transit (predicted) Mid Transit (predicted) Planet TrES-1 around GSC 2652:1324 Jupiter sized planet discovered in (R.Alonso et al) Sol magnitude star in Lyra (lying at ~ 500 ly distance) Orbital period 3.03 days. Transit duration ~ 2.5 hours, Transit depth mag Depth of magnitude dip being looked for 30s exposures (C Filter) Av 3 x 20s exp (C Filter) Attempted Transit Observation in C Filters, / 09
Improving my chances Transit Opportunities - Dates/Times /Airmass Transit Opportunities - Dates/Times /Airmass Screening worksheet/charts Screening worksheet/charts Baseline Images for each candidate Baseline Images for each candidate Central Image Positions, Reference Stars, Exposure Times Central Image Positions, Reference Stars, Exposure Times Better Flat fields Better Flat fields Not realistically feasible with current focuser, due to gravity droop on CCD camera (option to invest in new heavy duty focuser, but avoiding at this stage) Not realistically feasible with current focuser, due to gravity droop on CCD camera (option to invest in new heavy duty focuser, but avoiding at this stage) Anti-Dew System Anti-Dew System New power source installed in early 2007 has fixed previous problem with dew heater New power source installed in early 2007 has fixed previous problem with dew heater Reduction in star drift / keep stars fixed on same pixels Reduction in star drift / keep stars fixed on same pixels Improved Polar Alignment (aiming for less than 1 arc min, current misalignment is 3.4 arc min ) Improved Polar Alignment (aiming for less than 1 arc min, current misalignment is 3.4 arc min ) Guiding between frames with new script that is robust to passing cloud Guiding between frames with new script that is robust to passing cloud Robust Software / Procedures Robust Software / Procedures Software thats going to work on that one ideal night when conditions are perfect Software thats going to work on that one ideal night when conditions are perfect Focus / FWHM monitoring Focus / FWHM monitoring Script to monitor FWHM / sky brightness in realtime Script to monitor FWHM / sky brightness in realtime Better prediction of Clear Weather & Good Seeing Better prediction of Clear Weather & Good Seeing Weather forecasts / Jet Stream monitoring Weather forecasts / Jet Stream monitoring
Screening Transit Opportunities
HD – good candidate in Vulpecula mag +7.67, transit depth mag ref star mag +8.1
Results from guiding between frames
Practice Photometry (non exoplanet star)
Weather Total Cloud Cover on Sun Sept 2 nd, 23:00 (on the day forecast) Total Cloud Cover Forecast for Sun Sept 2 nd, 23:00 (2 ½ days prior)
Latest Attempt : WASP-1 Transit Depth of magnitude dip being looked for (0.011 m)
Pointing Accuracy during WASP-1 Transit Attempt,
How close ?
HD opportunity,
HD opportunity,