7508( 31) - 12/01/00 21:46 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7508 Version: 31 Check-in Date: 01-Dec-2000 21:45:10 1.Proposal Title: Ultraviolet Line Eclipses by Extrasolar Planets ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Gibor Basri University of California - Berkeley CoI: Jeff Valenti National Optical Astronomy Observatories, N Kitt Peak CoI: Geoff Marcy San Fransisco State University & UC N Berkeley CoI: Fred Walter State University of New York, Stonybrook N CoI: Frank Wilkin University of California at Berkeley N CoI: Hyron Spinrad University of California at Berkeley N CoI: John Clarke University of Michigan N ------------------------------------------------------------------------------------ 5. Abstract One of the most exciting events in Astronomy last year was the discovery of extrasolar planets. Even more exciting was the character of these planets. Several were found to be around the mass of Jupiter, yet located extremely close to their stars (4 day orbital periods). While no other plausible explanation for the Doppler variations which signal their presence has been found, it would obviously be very important if we could confirm the presence of physical bodies in orbit, and begin to study their properties. Though there is reason to believe these systems are seen almost edge on, direct eclipses by the planets have been ruled out. The planets are likely to be losing a lot of hydrogen from their exospheres due to their proximity to the stars. We will look for eclipses due to Lyman alpha clouds around the short period planets orbiting 51 Peg and Tau Boo. The expected size of the Lyman- alpha clouds gives us 4 times the range of orbital inclination in which to see eclipses. We will observe the stars during two consecutive transits to distinguish between intrinsic variability and perodic phenomena. This experiment has a plausible chance of succeeding, with very exciting results if it does. ------------------------------------------------------------------------------------ 7508( 31) - 12/01/00 21:46 - [ 2] Observations Description ------------------------ We are looking for changes in Lyman-alpha during transits of planetary companions of Tau Boo, 51 Peg, and HD 209458. We will use the medium resolution G140M grating in the 1222 Angstrom setting. Each star will be observed for two or three orbits near transit, and then again for two orbits during the next transit. Current ephemerides predict transit times to within 10 minutes. Uncertainty increases as the ephemerides are projected into the future. Transits are a couple of hours in duration. We use PERIOD AND ZERO-PHASE to specify target characteristics and then PHASE TO to constrain observing times. To force second visits for certain targets to be one period later, we use AFTER BY TO. All observations are in TIMETAG mode so we can reconstruct the transit behavior. With only two orbits per transit, this is rather important. Based on scaled Alpha Cen profiles, the global count rate is expected to be less than 20 counts/sec. Any BUFFER-TIME will suffice. Similarly, the total event count will not burden the data recorder. Peak S/N per wavelength pixel is predicted to be 22 per visit for Tau Boo and 34 for 51 Peg. HD 209458 was added to the program after the second visit to 51 Peg failed. HD 209458 is known to have a planetary transit. Mazeh et al. (2000, ApJ, 532, L55) give a planetary period of 3.524739+/-0.000014 days and a radial velocity of -14.7652+/-0.0016 km/s. Given the coordinates and radial velocity of HD 209458, stellar Lyman-alpha will be maximally blueshifted by 40.4 km/s on June 1 and maximally redshifted by +11.6 km/s on Dec 3. The Lyman-alpha profiles of 51 Peg and Tau Boo are essentially identical after multiplying the Tau Boo spectrum by a factor of 2.0. The profile consists of a 260 km/s wide profile with an 80 km/s wide central reversal. Detection of the transit is likely to have the largest effect in the unsaturated portion of the Lyman-alpha profile, i.e. out of the saturated absorption core. Thus, the stellar profile should not be shifted by more the +/ -40 km/s (and preferably less than +/-20 km/s) relative to the geocoronal line to keep the geocoronal line in the saturated core of the stellar line. The +/- 20 km/s observing constraint translates into a preferred date range of Aug 21 through Mar 14, though any time of year is acceptable. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- There is some advantage to scheduling the observations at a time when geocoronal emission will be maximally displaced from the stellar rest frame. This occurs in August for 51 Peg, and in February for Tau Boo. However, getting the planetary transit time right is a much more important constraint. Geoff Marcy will obtain new observations of 51 Peg in June, allowing us to determine a precise ephemeris. Thus, August 1997 would be an ideal time to observe 51 Peg, since very little error would have accumulated in the new ephemeris. For Tau Boo, we are hoping to have a new ephemeris ready at the beginning of 1998. ------------------------------------------------------------------------------------ 7508( 31) - 12/01/00 21:46 - [ 3] Data Distribution Paper Products: YES Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7508( 31) - 12/01/00 21:46 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD120136 STAR, F3-F9 RA=13H 47M 15.69S +/- 0.1", J2000 V = - V = 4.50+/-0.01 DEC=17D 27' 23.7" +/- 0.1" 15.6 B-V = 0.48+/-0.01 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 -0.03368 0.041 0.056 2 HD217014 STAR, G V-IV RA=22H 57M 27.96S +/- 0.05", J2000 V = - V = 5.49+/-0.01 DEC=20D 46' 7.1" +/- 0.05" 32.7 B-V = 0.67+/-0.01 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 0.01440 0.043 0.073 3 HD209458 STAR, F3-F9 RA=22H 03M 10.75S +/- 0.1", J2000 V = - V = 7.65 DEC=18D 53' 3.7" +/- 0.1" 14.7652 B-V = 0.53 Coordinate Source: HIPPARCOS/TYCHO_CATALOGUE Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 0.0023 -0.0190 0.0212 7508( 31) - 12/01/00 21:46 - [ 5] Visit: 01 Visit Priority: Visit Requirements: BETWEEN 09-Jun-1999:15:55:50 and 09-Jun-1999:20:09:40 BETWEEN 19-Jun- 1999:14:28:35 and 19-Jun-1999:18:42:23 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HD120136 STIS/C ACQ F28X50O MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 30 CD II ------------------------------------------------------------------------------------------------------------------------------------ 20 HD120136 STIS/C ACQ/PEA 52X0.1 G430M 3680 1 1 S ONBOARD ACQ FOR 30 SAVE CD K OFFSET TAUBOO ------------------------------------------------------------------------------------------------------------------------------------ 30 HD120136 STIS/F TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 1530 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 40 HD120136 STIS/F TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 2550 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 7508( 31) - 12/01/00 21:46 - [ 6] Visit: 02 Visit Priority: Visit Requirements: BETWEEN 26-Jun-1999:07:38:52 and 26-Jun-1999:10:10:57 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HD120136 STIS/F TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 2320 S USE OFFSET TAUBOO UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 20 HD120136 STIS/F TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 2250 S USE OFFSET TAUBOO UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 7508( 31) - 12/01/00 21:46 - [ 7] Visit: 03 Visit Priority: Visit Requirements: BETWEEN 19-May-1999:03:03:51 and 19-May-1999:07:17:40 BETWEEN 31-May- 1999:19:40:45 and 31-May-1999:23:54:32 BETWEEN 05-Jun-1999:01:12:48 and 05- Jun-1999:05:26:36 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HD217014 STIS/C ACQ F28X50O MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 30 CD II ------------------------------------------------------------------------------------------------------------------------------------ 20 HD217014 STIS/C ACQ/PEA 52X0.1 G430M 3680 1 1 S ONBOARD ACQ FOR 30 SAVE CD K OFFSET 51PEG ------------------------------------------------------------------------------------------------------------------------------------ 30 HD217014 STIS/F TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 1530 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 40 HD217014 STIS/F TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 2550 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 7508( 31) - 12/01/00 21:46 - [ 8] Visit: 04 Visit Priority: Visit Requirements: BETWEEN 13-Jun-1999:13:57:39 and 13-Jun-1999:16:29:49 BETWEEN 01-Sep- 1999:22:20:06 and 02-Sep-1999:02:07:10 BETWEEN 14-Sep-1999:16:14:36 and 14- Sep-1999:18:45:56 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HD217014 STIS/F TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 2320 S USE OFFSET 51PEG UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 20 HD217014 STIS/F TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 2250 S USE OFFSET 51PEG UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 7508( 31) - 12/01/00 21:46 - [ 9] Visit: 54 Visit Priority: Visit Requirements: PERIOD 3.524737 D AND ZERO-PHASE JD2451497.797000 BETWEEN 21-Aug-2000 and 14-Mar-2001 BETWEEN 21-Aug-2001 and 14-Mar-2002 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HD209458 STIS/C ACQ F28X50O MIRROR 1 2.0 S CD II Comments: S/N=213.5, Peak=27600 e-, ETC 8984 ------------------------------------------------------------------------------------------------------------------------------------ 20 HD209458 STIS/C ACQ/PEA 52X0.1 G430L 4300 1 2 S END ORBIT CD K Comments: S/N=125@4301, Peak=5800 e-, Global=9760000 e- , ETC 9009 ------------------------------------------------------------------------------------------------------------------------------------ 40 HD209458 STIS/F TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=2600 1 2600 S PHASE 0.963 TO 0.973 UV-MAM G A Comments: 1.96-1.43 orbits (3.14-2.28 hours) before transit ------------------------------------------------------------------------------------------------------------------------------------ 50 HD209458 STIS/F TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=2600 1 2600 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 7508( 31) - 12/01/00 21:46 - [ 10] Summary Form for Proposal 7508 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50OII 52X0.1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT BUFFER-TIME=1000 BUFFER-TIME=2600 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 09-Jun-1999 15 55 50 and 09-Jun-1999 20 09 40 BETWEEN 19-Jun-1999 14 28 35 and 19-Jun-1999 18 42 23 ONBOARD ACQ FOR 30 ONBOARD ACQ FOR 30 SAVE OFFSET TAUBOO BETWEEN 26-Jun-1999 07 38 52 and 26-Jun-1999 10 10 57 USE OFFSET TAUBOO BETWEEN 19-May-1999 03 03 51 and 19-May-1999 07 17 40 BETWEEN 31-May-1999 19 40 45 and 31-May-1999 23 54 32 BETWEEN 05-Jun-1999 01 12 48 and 05-Jun-1999 05 26 36 ONBOARD ACQ FOR 30 SAVE OFFSET 51PEG BETWEEN 13-Jun-1999 13 57 39 and 13-Jun-1999 16 29 49 BETWEEN 01-Sep-1999 22 20 06 and 02-Sep-1999 02 07 10 BETWEEN 14-Sep-1999 16 14 36 and 14-Sep-1999 18 45 56 USE OFFSET 51PEG PERIOD 3.524737 D AND ZERO-PHASE JD2451497.797000 BETWEEN 21-Aug-2000 and 14-Mar-2001 BETWEEN 21-Aug-2001 and 14-Mar-2002 END ORBIT PHASE 0.963 TO 0.973 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G430M G140M G430L ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD120136 HD217014 HD209458 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 3680 1222 4300 ------------------------------------------------------------------------------------------------------------------------------------