! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6676,v 6.1 1996/11/20 18:24:56 pepsa Exp $ ! ! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Karla Peterson ! Phone: 410-338-4774 , E-mail: peterson@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. Proposal_Information ! Section 4 Title: Rapid UV Variability: The Contribution of Flare Heating in the Atmospheres of Active, Evolved Stars Proposal_Category: GO Scientific_Category: COOL STARS Cycle: 6 Investigators PI_name: Dr. Steven Saar PI_Institution: Smithsonian Astrophysical Observatory CoI_Name: Dr. Jay Bookbinder CoI_Institution: Smithsonian Astrophysical Observatory Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) The question of the contribution of flares and microflares to the non-radiatively heated outer atmospheres of late-type stars has been studied with very limited success for over a decade using IUE, a variety of X--ray satellites, and ground- based studies. HST presents the best opportunity to place a firm lower limit on the fraction of the transition region flux resulting from short timescale events. Our analysis of HST data on one M dwarf shows that up to 60\% of the transition region flux is directly attributable to stellar flares and microflares. This leaves little room for the traditional ``quiescent" emission. Such a result, if confirmed for other stars, promises to revitalize the study of their outer atmospheres, with the recognition that they are far more dynamic than static. We now propose to observe two active, evolved stars to probe the importance of flare heating in their outer atmospheres: the RS CVn binary II Peg, and FK Comae, a rapidly rotating single giant (possibly the result of a coalesced binary). It is important to make these observations before STIS, since the even moderate flares on these stars could saturate the MAMA detectors in strong lines. Questions ! Free format text (please update) Observing_Description: The GHRS G140L grating (LSA), centered at 1433 A, will be employed to study a series of both chromospheric lines and transition region lines. This setting will allow us to study variability in : C II (1340 A) and the O I (1305 A) line (if we can work around the geocoronal O I contribution); and the Si IV (1400 A) and C IV (1550 A) lines for the transition region. That C IV and Si IV are formed at very similar temperatures, can be used to help confirm our variability analysis - both lines must register valid events. The G140L grating of the GHRS was selected primarily because of its higher sensitivity and lower scattered light below 1500 A, where most of the lines lie, enabling us to take shorter observations than had we used the FOS. IUE measurement have established flux at earth of f(C IV) = 1.0E-12 ergs/cm**2/s/A for II Peg (Simon \& Fekel 1987). With an efficiency of 67E+11 counts/s/diode per incident ergs/cm**2/s/A at C IV for the G140L, we should obtain 6.7 counts/s at C IV for II Peg. Since during flares this value can easily increase this by a factor of 10 or more, we should have ample counts to study flares and microflares in these stars. Note that even moderate (7 x) flares require the GHRS, as the STIS MAMA's will saturate above 50 counts/s/pixel (the largest flare in our AD Leo observations, still quite small by dMe standards, showed a 90 times enhancement in C IV; Bookbinder et al. 1992). Our request of 2 orbits will yield approximately 1 hour of on target observations for each star. Real_Time_Justification: Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: We plan an extensive suite of coordinated observations for our targets. Optical spectra of chromospheric diagnostics as well as photometry are planned. We will attempt doppler imaging and magnetic doppler imaging (e.g., Saar et al. 1992) of II Peg and direct magnetic field measurements with the CSHELL at NASA's IRTF. Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: HD224085 Alternate_Names: II-PEG Description: STAR,K V-IV Position: RA=23H 55M 04.05S +/- 0.1S, DEC=28D 38' 01.3" +/- 0.3", ! Most common specification format is ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: J2000 RV_or_Z: V= -18.1 RA_PM: 0.044 ! Units are seconds of time per year Dec_PM: 0.027 ! Units are seconds of arc per year Epoch: J2000 Annual_Parallax: 0.034 +/- 0.004 Flux: V = 7.4 +/- 0.2 ! Include at least V and B-V B-V = 1.01 +/- 0.05 F-LINE(1550.0) = 1.0 +/- 0.5 E-12 W-LINE(1550.0) = 1.0 +/- 0.2 Comments: HIPPARCOS COORDINATES USED DUE TO STAR BRIGHTNESS ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed Visits ! Section 6 Visit_Number: 01 Visit_Requirements: BETWEEN 10-AUG-1996 AND 20-DEC-1996 ! Section 7.1 ! Uncomment or copy visit level special requirements needed On_Hold_Comments: Visit_Comments: "BETWEEN" DATES NOT AN ABSOLUTE REQUIREMENT, BUT HIGHLY DESIREABLE FOR COORDINATION WITH GROUND-BASED OBSERVATIONS Exposure_Number: 10 ! Section 6.5 Target_Name: HD224085 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N2 Wavelength: Optional_Parameters: BRIGHT=RETURN Number_of_Iterations: 1 Time_Per_Exposure: 1.8S Special_Requirements: ONBOARD ACQ FOR 20-30 ! Section 7.2 Comments: PLEASE NOTIFY P.I. WHEN DATES ARE SCHEDULED OR CHANGED (FOR COORDINATED OBSERVATIONS) IN ACQ EXPECT ABOUT 10500 CTS/S, HENCE STEP-TIME 0.2 SEC Exposure_Number: 20 ! Section 6.5 Target_Name: HD224085 Config: HRS Opmode: RAPID Aperture: 2.0 Sp_Element: G160M Wavelength: 1550.0 Optional_Parameters: SAMPLE-TIME=10.0 Number_of_Iterations: 1 Time_Per_Exposure: 1715S Special_Requirements: ! Section 7.2 Exposure_Number: 30 ! Section 6.5 Target_Name: HD224085 Config: HRS Opmode: RAPID Aperture: 2.0 Sp_Element: G140L Wavelength: 1433.0 Optional_Parameters: SAMPLE-TIME=1.0 Number_of_Iterations: 1 Time_Per_Exposure: 2638S ! *** ??? *** Special_Requirements: ! Section 7.2 Data_Distribution ! Defaults indicated; change if desired Medium: 8MM ! 8MM or 6250BPI or 1600BPI Blocking_Factor: 10 ! 10 or 1 ! Only astronomers with very old 9- ! track tape drives should consider ! a blocking factor of 1 Ship_To: PI_Address ! STSCI or PI_Address or ! PI Address from Phase I is: ! ! Mail Stop 58 ! 60 Garden St. ! Cambridge ! 02138 ! ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense Recipient_Email: ! Needed if Ship_To: is not PI_Address ! ! Let us know what you think of this template and software! ! Please send a list of your likes and dislikes to your Program Coordinator