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PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only
ID: 6492
Version: 5
Check-in Date: 17-Mar-1997
10:36:43
1.Proposal Title:
High Resolution Imaging of the Massive Overcontact Binary RY Scuti
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2. Scientific Category 3. Proposal For 4. Cycle
BINARIES AND STAR FOR GO 6
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5. Investigators
Contact?
PI: ROBERT D. GEHRZ UNIVERSITY OF MINNESOTA
CoI: Terry Jones University of Minnesota Y
CoI: Roberta Humphreys University of Minnesota N
CoI: Kris Davidson University of Minnesota N
CoI: Joachim Krautter University of Heidelberg N
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6. Abstract
RY Scuti is a post-main sequence, eclipsing, 'overcontact' binary. The two
components are very massive, 49 and 39 M_\odot , with a combined luminosity in
excess of 3* 10^6L_\odot . Ground based observations have established that this star
is surrounded with a very unusual nebula about 1 arcsecond in extent containing both
ionized gas and thermally emitting dust. The Ne abundance in the nebula is well
above solar composition, indicating the system is at a critical phase of its
evolution. We propose to image the nebulosity around RY Scuti to investigate its
morphology and the mass loss process in the system. We will use these images to
distinguish between hypothesized mass loss scenarios and to study the interface
between the plasma and dust regions of the nebula.
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Observations Description
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RY Scuti is a relatively bright object (V = 9.1, B = 10.1) surrounded by faint
nebulosity. We have planned a series of exposures in V (F547M), B (F467M) and
HAlpha (F656N) with the shortest chosen to avoid bleeding from the central star
and the longest to image the fainter outer parts of the nebula. The exposure
times are: 0.5s, 3s, 20s, 60s in V; 10s, 50s, 250s in B; 15s, 75s, 400s in
HAlpha . With standard allowances for acquisition and overhead time this fills
one orbit. begintabularlll Cycle 6 & Primary Orbits:1 & Exposures:10,
endtabular
Real Time Justification
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None. R. D. Gehrz and J. Krautter will be obtaining supporting ground-based
near-IR imaging observations using IRAC-2 on the 2.3-m telescope and mid-IR
imaging observations using the TIMMI camera on the 3.6-m telescope at ESO.
Calibration Justification
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Additional Comments
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Data Distribution
Media: 8MM
Blocking Factor: 10
Ship To: PI_Address
Ship Via: UPS
Email:
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TARGET LIST a) Fixed Targets
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Tar| Target | Target | Target |Coord | Radial | Flux data
No | Name | Description | Position |Eqnx | Vel. |
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100 HD169515 STAR,SUPERGIANT RA=18H 22M 42.706S +/- 1950 V = 9.1+/-0.1
O,INTERACTING BINARY 0.0011S,DEC=-12D 43' 9.24" +/- B-V = 1.06+/-0.05
0.005" E(B-V) = 1.37+/-0.1
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Visit: 01
Visit Requirements: <none>
On Hold Comments: <none>
Additional Comments: <none>
Exposures
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Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special
Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements
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101 HD169515 WFPC2 IMAGE PC1 F467M ATD-GAIN=15 1 2 S SEQ 101-303 NON-INT
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102 HD169515 WFPC2 IMAGE PC1 F467M DITHER-TYPE=LINE, 2 100 S
DITHER-LINE-SPACING=0.161
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301 HD169515 WFPC2 IMAGE PC1 F656N ATD-GAIN=15 1 5 S
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302 HD169515 WFPC2 IMAGE PC1 F656N 2 20 S
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303 HD169515 WFPC2 IMAGE PC1 F656N DITHER-TYPE=LINE, 1 120 S
DITHER-LINE-SPACING=0.161
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Summary Form for Proposal 6492
Item Used in this proposal
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Configurations WFPC2
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Opmodes IMAGE
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Optional Parameters ATD-GAIN=15 DITHER-LINE-SPACING=0.161 DITHER-TYPE=LINE
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Proposal Category GO
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Scientific Category BINARIES AND STAR FORMATION
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Special Requirements SEQ 101-303 NON-INT
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Spectral Elements F467M F656N
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Target Names HD169515
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