6506( 5) - 04/17/96 16:27 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6506 Version: 5 Check-in Date: 17-Apr-1996 16:23:02 1.Proposal Title: High Resolution Imaging of Young Stellar Objects in Serpens ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Binaries and Star For GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Patrick Roche University of Oxford CoI: Mr. Philip Lucas Oxford Y ------------------------------------------------------------------------------------ 6. Abstract Optical and Near Infrared Imaging of nearby Young Stellar Objects at high spatial resolution is beginning to reveal their circumstellar structures on the scale of the solar system. The Serpens Molecular Cloud contains about fifty embedded sources within two arcminutes of the central Serpens Reflection Nebula. The extinction is generally less than in other star forming regions and several cometary nebulae have been observed with ground based telescopes at a wavelength of 0.95Mu. These two factors make the Serpens Cloud especially well suited for high resolution optical imaging of protostars at the pre-T Tauri stage of their evolution. We have recently performed high resolution near infrared observations of the region and detected infalling envelopes of dust and gas which surround the protostars and a candidate protoplanetary disk in the core of the Serpens Reflection Nebula. We propose to image the Serpens Cloud with WFPC-2 using the HAlpha, R and I filters. The high resolution and dynamic range of HST will allow investigation of the inner structure of the envelopes and wind-evacuated bipolar cavities of a large number of protostars observed at different orientations. The data can then be combined with our near infrared data and used to constrain theoretical models of scattered light images developed at Oxford. We can then attempt to determine the masses of the circumstellar structures and the properties of the dust grains. ------------------------------------------------------------------------------------ 6506( 5) - 04/17/96 16:27 - [ 2] Observations Description ------------------------ We wish to image 2 fields of particular interest with the PC and simulataneously use the 3 CCDs of the WFC to image the most of the remainder of the cloud. Each field will require 1 orbit and will be imaged in the I band (F814W), R Band (F675W) and in Halpha (F656N). For example field 2 is centred at : (18 29 57.08, +01 12 48.9) J2000.0 in order to capture at least 5 sources within the PC field at maximum resolution. Two 5 minute integrations in each filter will provide a large dynamic range without saturation and allowing cosmic ray removal. guide star acquisition and alignment 13 minutes 6x5 minute exposures 30 minutes 6 CCD reads 6 minutes 3 filter settings 3 minutes Total 52 minutes Orbit Visibility 52 minutes Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6506( 5) - 04/17/96 16:27 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SERPENS- ISM,BIPOLAR RA=18H 29M 57.08S +/- J2000.0 I = 18.9+/-0.5 CLOUD-SVS4- OUTFLOW,COMETARY 0.2S,DEC=01D 12' 48.9" +/- 3.0" CLUSTER NEBULA,MOLECULAR CLOUD,STELLAR CLUSTER,T Comments: Several stellar sources and extended nebulosity of varying intensity in this field. Field is centred in the middle of the cluster. Magnitudes given for brightest source. 2 SERPENS- ISM,BIPOLAR RA=18H 29M 56.77S +/- J2000.0 I = 15.0+/-0.5 CLOUD-SVS2 OUTFLOW,COMETARY 0.2S,DEC=01D 14' 46.1" +/- 3.0" R = 16.6+/-0.6 NEBULA,MOLECULAR R-I = 1.6+/-0.5 CLOUD,STELLAR CLUSTER,T Comments: Source has stellar core and extended nebulosity of varying intensity which will fill the PC field. 6506( 5) - 04/17/96 16:27 - [ 4] Visit: 01 Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 SERPENS- WFPC2 IMAGE PC1 F656N CLOCKS=YES 1 260S POS TARG 0.0,0.0 CLOUD-SVS4- CLUSTER Comments: CLOCKS=YES is used to reduce overhead on all the exposures between 3 and 10 minutes. ------------------------------------------------------------------------------------------------------------------------------------ 2 SERPENS- WFPC2 IMAGE PC1 F675W CLOCKS=YES 1 260S SAME POS AS 1 CLOUD-SVS4- CLUSTER ------------------------------------------------------------------------------------------------------------------------------------ 3 SERPENS- WFPC2 IMAGE PC1 F814W CLOCKS=YES 1 260S SAME POS AS 1 CLOUD-SVS4- CLUSTER ------------------------------------------------------------------------------------------------------------------------------------ 4 SERPENS- WFPC2 IMAGE PC1 F814W CLOCKS=YES 1 260S POS TARG 0.25,0.25 CLOUD-SVS4- CLUSTER ------------------------------------------------------------------------------------------------------------------------------------ 5 SERPENS- WFPC2 IMAGE PC1 F675W CLOCKS=YES 1 260S SAME POS AS 4 CLOUD-SVS4- CLUSTER ------------------------------------------------------------------------------------------------------------------------------------ 6 SERPENS- WFPC2 IMAGE PC1 F656N CLOCKS=YES 1 260S SAME POS AS 4 CLOUD-SVS4- CLUSTER ------------------------------------------------------------------------------------------------------------------------------------ 7 SERPENS- WFPC2 IMAGE PC1 F656N CLOCKS=YES 1 260S POS TARG 0.0,0.0 CLOUD-SVS2 ------------------------------------------------------------------------------------------------------------------------------------ 8 SERPENS- WFPC2 IMAGE PC1 F675W CLOCKS=YES 1 260S SAME POS AS 7 CLOUD-SVS2 ------------------------------------------------------------------------------------------------------------------------------------ 9 SERPENS- WFPC2 IMAGE PC1 F814W ATD-GAIN=7 1 20S SAME POS AS 7 CLOUD-SVS2 ------------------------------------------------------------------------------------------------------------------------------------ 10 SERPENS- WFPC2 IMAGE PC1 F814W CLOCKS=YES 1 300S SAME POS AS 7 CLOUD-SVS2 ------------------------------------------------------------------------------------------------------------------------------------ 11 SERPENS- WFPC2 IMAGE PC1 F814W CLOCKS=YES 1 300S POS TARG 0.25,0.25 CLOUD-SVS2 ------------------------------------------------------------------------------------------------------------------------------------ 12 SERPENS- WFPC2 IMAGE PC1 F675W CLOCKS=YES 1 260S SAME POS AS 11 CLOUD-SVS2 ------------------------------------------------------------------------------------------------------------------------------------ 13 SERPENS- WFPC2 IMAGE PC1 F656N CLOCKS=YES 1 260S SAME POS AS 11 CLOUD-SVS2 ------------------------------------------------------------------------------------------------------------------------------------ 6506( 5) - 04/17/96 16:27 - [ 5] Summary Form for Proposal 6506 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CLOCKS=YES ATD-GAIN=7 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Binaries and Star Formation ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG 0.0,0.0 SAME POS AS 1 POS TARG 0.25,0.25 SAME POS AS 4 SAME POS AS 7 SAME POS AS 11 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F656N F675W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SERPENS-CLOUD-SVS4-CLUSTER SERPENS-CLOUD-SVS2 ------------------------------------------------------------------------------------------------------------------------------------