! $Id: 6343,v 8.1 1996/06/11 13:40:41 pepsa Exp $ 6343 ! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! ! For help call your Program Coordinator: Alice Berman ! Phone: 410/338-4462, E-mail: aberman@stsci.edu ! Proposal_Information ! Section 4 Title: Finding the Lyman-alpha Cloud Around 51 Peg B with GHRS Proposal_Category: GO/DD Scientific_Category: ! Uncomment one of the following Cool Stars ! Solar System ! Stellar Populations Cycle: 5 Investigators PI_Name: Hyron Spinrad PI_Institution: University of California at Berkeley CoI_Name: Gibor Basri CoI_Institution: University of California at Berkeley Contact: ! Y or N (designate at most one contact) CoI_Name: Frederick Walter CoI_Institution: State University of New York at Stony Brook Contact: ! Y or N (designate at most one contact) CoI_Name: Geoff Marcy CoI_Institution: Contact: ! Y or N (designate at most one contact) CoI_Name: Michel Mayor CoI_Institution: Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (clear and concise) One of the most exciting recent developments in Astronomy has been the discovery of radial velocity variations in the solar-type star 51 Peg which imply the existence of a Jupiter sized planet around it. The orbit is astonishingly close to the star (0.05 AU) for a giant planet. Analysis shows, however, that the planet could retain its atmosphere even so close. The chromospheric inactivity of the star, combined with a detectable rotational velocity, imply that the system is viewed nearly edge on. Attempts to find a photometric eclipse have turned up nothing. The exosphere of the planet is subject to strong high energy fluxes from the star, making it likely that there is a neutral hydrogen corona around the planet. This might be quite extensive, depending on its magnetosphere. We propose to look for absorption of stellar Lyman-alpha by the planetary corona, which would constitute hard physical evidence that a body is really there. In particular, we will compare the profile during and away from transit. Questions ! Free format text (clear and concise) Observing_Description: We will observe the Lyman-alpha line at medium resolution for 3 successive orbits centered on the transit of the putative planet. We hope to see an absorption feature in the stellar Lyman-alpha line due to a possible cloud of Hydrogen surrounding the planet. Observations are phase-critical: the second of the observations is centered on the expected time of transit. The uncertainties in the ephemeris become large (a few hours) when extrapolated to mid-1996. We will update the ephemeris in the spring. (Note: this has been done). Observations are in the SSA to minimize geocoronal contamination. 51 Peg has a radial velocity of -31 km/s. In June the Earth's orbital motion around the Sun gives 51 Peg a 60 km/s separation from the geocoronal emission. The observation is time critical in order to maximize the separation of the stellar and geocoronal lines. Real_Time_Justification: N/A Calibration_Justification: N/A Additional_Comments: NOTE: THIS OBSERVATION IS TIME- and PHASE- CRITICAL. SEE Visit-Comments Fixed_Targets Target_Number: 1 Target_Name: 51-PEG Alternate_Names: HD217014, GSC1717-2193 Description: STAR, G V-IV Position: RA=22H 57M 27.96S +/- .03S, DEC=20D 46' 7.1" +/- .3" ! PLATE-ID=+056 Equinox: J2000 RV_or_Z: V=-31.2 RA_PM: 0.0142 ! Units are seconds of time per year Dec_PM: 0.059 ! Units are seconds of arc per year Epoch: 2000 Annual_Parallax: 0.073 Flux: V=5.49+/-0.02, B-V=0.67+/-0.02 Comments: Visits Visit_Number: 1 Visit_Requirements: ! PERIOD 4.2318D AND ZERO-PHASE JD2450238.86120 On_Hold_Comments: Visit_Comments: Visit must be scheduled when geocentric radial velocity is <-55, between 15-JUN-96 AND 20-JUL-96, to facilitate separation of stellar and geocoronal Lyman-alpha. Phase 0 must occur in second orbit. Ephemeris will be updated be early May, hence the restricted range of dates. Exposure_Number: 10 ! Section 6.5 Target_Name: 51-PEG Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N2 Optional_Parameters: BRIGHT=RETURN,SEARCH-SIZE=3 Number_of_Iterations: 1 Time_Per_Exposure: 1.8S Special_Requirements: ONBOARD ACQ FOR 12 Comments: STEP-TIME=0.2S Exposure_Number: 12 Target_Name: 51-PEG Config: HRS Opmode: ACQ/PEAKUP Aperture: 0.25 Sp_Element: MIRROR-N2 Optional_Parameters: SEARCH-SIZE=5 Number_of_Iterations: 1 Time_Per_Exposure: 5.0S Special_Requirements: ONBOARD ACQ FOR 20-41 Comments: STEP-TIME=0.2S Exposure_Number: 20 ! Section 6.5 Target_Name: 51-PEG Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: G160M Wavelength: 1215 Optional_Parameters: STEP-PATT=5 Number_of_Iterations: 4 Time_Per_Exposure: 272.0S Special_Requirements: SEQ 20 NON-INT Comments: TIME CRITICAL. MUST START BETWEEN 15-JUN-96 AND 20-JUL-96 Exposure_Number: 30 Target_Name: 51-PEG Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: G160M Wavelength: 1215 Optional_Parameters: STEP-PATT=5 Number_of_Iterations: 9 Time_Per_Exposure: 272.0S Special_Requirements: SEQ 30-31 NON-INT ! PHASE 0.994 TO 0.998; Comments: CENTER ON PLANET TRANSIT Exposure_Number: 31 Target_Name: 51-PEG Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: G160M Wavelength: 1215 Optional_Parameters: STEP-PATT=5 Number_of_Iterations: 1 Time_Per_Exposure: 27.2S Special_Requirements: Comments: Exposure_Number: 40 Target_Name: 51-PEG Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: G160M Wavelength: 1215 Optional_Parameters: STEP-PATT=5 Number_of_Iterations: 9 Time_Per_Exposure: 272.0S Special_Requirements: SEQ 40-41 NON-INT Comments: Exposure_Number: 41 Target_Name: 51-PEG Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: G160M Wavelength: 1215 Optional_Parameters: STEP-PATT=5 Number_of_Iterations: 1 Time_Per_Exposure: 27.2S Special_Requirements: Comments: Data_Distribution ! Defaults indicated; change if desired Medium: 8MM ! 8MM or 6250BPI or 1600BPI Blocking_Factor: 10 ! 10 or 1 Ship_To: Frederick M. Walter ESS Dept, Z=2100 SUNY Stony Brook, NY 11794-2100 Ship_Via: UPS ! UPS (2-day) or OVERNIGHT Recipient_Email: fwalter@astro.sunysb.edu