! HST PROPOSAL 5310 Proposal_Information Title: AB DORADUS: THE KEY OBJECT OF STELLAR ACTIVITY Proposal_Category: GO Scientific_Category: COOL STARS,STELLAR ACTIVITY Cycle: 4 Investigators PI_name: VILHU, OSMI PI_Institution: University of Helsinki Questions Observing_Description: Real_Time_Justification: Calibration_Justification: Additional_Comments: Abstract: AB Doradus (K2IV) is the best target to study stellar activity at high levels. It has many important properties to have a high priority for ST UV-observations: 1.) It is bright (V=6.9) and its chromospheric-transition region line fluxes are among the highest ones and easily accessible for GHRS-observations. 2.) Its activity at different wavelengths can be modelled by a rather stable geometry (see Fig.3) which is very suitable for Doppler-imaging and interpretation. 3.) The rotation period is short (12 hours) permitting significant results in a reasonable observation time. 4.) With a high probability major UV-X ray flares take place during one rotation cycle. High resolution observations of TR region lines during the flares are physically crucial. 5.) Co-rotating transients at several stellar radii, carrying out angular momentum from the star, can be observed in 12 hours. 5.) AB Doradus (Delta = -65 deg) lies in the continuos viewing zone. This is valuable if 12 hours of spacecraft time will be allocated. Then no flares nor transients will be lost. We propose that AB Doradus will be observed continuosly during 12 hours of total spacecraft time with the G160M grating. Its resolving power (20000) is ideal for the star's rotational velocity (100 km/s). The region around CIV 1550 will be observed with 3 min time resolution. This is optimal for flares and transients, for the Doppler-imaging spectra will be co-added. Fixed_Targets Target_Number: 1 Target_Name: HD36705 Alternate_Names: AB-DORADUS Description: STAR,K V-IV,T TAURI STAR,FK COMAE STAR, Position: RA=5H 28M 44.8S +/- 0.030S, DEC= -65D 26' 56.8" +/- 0.40", PLATE-ID=02I7 Equinox: J2000 Epoch: J2000 Rv_or_z: V = 29.0 RA_PM: 0.0084 Dec_PM: 0.135 Annual_Parallax: 0.04 Flux: V = 6.9 +/- 0.1, B-V = 8.299999999999999 +/- 0.3 E-1, E(B-V) = 30.0 +/- 20.0 E-3, F-LINE(1550.0) = 12.0 +/- 3.0 E-13, W-LINE(1550.0) = 5.0 +/- 1.0 E-1 Comments: THIS IS A CVZ TARGET. Target_Number: 2 Target_Name: HD36705-FIX Alternate_Names: AB-DORADUS Description: STAR,K V-IV,T TAURI STAR,FK COMAE STAR, Position: RA=5H 28M 44.84S +/- 0.030S, DEC= -65D 26' 55.4" +/- 0.40" Equinox: J2000 Epoch: J2000 Rv_or_z: V = 29.0 RA_PM: 0.00802 +/- .0006 Dec_PM: 0.131 Annual_Parallax: 0.04 Flux: V = 6.9 +/- 0.1, B-V = 8.299999999999999 +/- 0.3 E-1, E(B-V) = 30.0 +/- 20.0 E-3, F-LINE(1550.0) = 12.0 +/- 3.0 E-13, W-LINE(1550.0) = 5.0 +/- 1.0 E-1 Comments: THIS IS A CVZ TARGET. Hipparcos Coords and proper motion values. Visits Visit_Number: 01 Visit_Requirements: On_Hold_Comments: ! From Line 1 Exposure_number: 10 Target_Name: HD36705 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N2 Wavelength: Optional_Parameters: BRIGHT=RETURN, SEARCH-SIZE=3 Number_of_iterations:1 Time_Per_Exposure: 3.6S Special_Requirements:ONBOARD ACQ FOR 20 Comments: PLEASE NOTIFY P.I. WHEN DATES ARE SCHEDULED OR CHANGED (FOR COORDINATED OBSERVATIONS) IN ACQ EXPECT ABOUT 23000 CTS/S, HENCE STEP-TIME 0.4 SEC ! From Line 2 Exposure_number: 20 Target_Name: HD36705 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: G160M Wavelength: 1549.0 Optional_Parameters: COMB=FOUR, STEP-PATT=DEF, DOPPLER=DEF, FP-SPLIT=STD Number_of_iterations:151 Time_Per_Exposure: 3M Special_Requirements: Comments: THESE EXPOSURES SHOULD BE SCHEDULED WHEN THE TARGET IS IN THE CVZ. TOTAL POINTING TIME 12 H. WE NEED SMALL DEAD-TIMES . IF LESS THAN 1 MIN OVHD TIME POSSIBLE, CONSIDER TO DO SHORTER AND MORE EXP'S Visit_Number: 02 Visit_Requirements: CVZ Visit_Comments: Visit 1 failed. Visit 2 is the repeat observation. Exposure_number: 10 Target_Name: HD36705-FIX Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N2 Wavelength: Optional_Parameters: BRIGHT=RETURN, SEARCH-SIZE=3 Number_of_iterations:1 Time_Per_Exposure: 3.6S Special_Requirements:ONBOARD ACQ FOR 15-20 Comments: PLEASE NOTIFY P.I. WHEN DATES ARE SCHEDULED OR CHANGED (FOR COORDINATED OBSERVATIONS) IN ACQ EXPECT ABOUT 23000 CTS/S, HENCE STEP-TIME 0.4 SEC Exposure_number: 15 Target_Name: HD36705-FIX Config: HRS Opmode: IMAGE Aperture: 2.0 Sp_Element: MIRROR-N2 Wavelength: Optional_Parameters: Number_of_iterations:1 Time_Per_Exposure: 51.2S Special_Requirements: Comments: Specified the minimum legal exposure time for 16x16 pixels Exposure_number: 20 Target_Name: HD36705-FIX Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: G140L Wavelength: 1435 Optional_Parameters: COMB=FOUR, STEP-PATT=4, DOPPLER=DEF, FP-SPLIT=NO Number_of_iterations:32 Time_Per_Exposure: 576S Special_Requirements: Comments: WE NEED SMALL DEAD-TIMES. IF LESS THAN 1 MIN OVHD TIME POSSIBLE, CONSIDER TO DO SHORTER AND MORE EXP'S Data_Distribution Medium: 8MM Blocking_Factor: 10 Ship_To: PI_Address Ship_Via: UPS Recipient_Email: