0Assigned ID: 152
----- Attempting Submission 1 (Wed Apr 05 16:48:44 GMT 2017) -----
HST Phase I Proposal 152 (VYphase1-GO.apt) successfully submitted.
Receipt: # 152-1
----- Attempting Submission 2 (Wed Apr 05 16:56:51 GMT 2017) -----
HST Phase I Proposal 152 (VYphase1-GO.apt) successfully submitted.
Receipt: # 152-2
----- Attempting Submission 3 (Thu Apr 06 14:27:08 GMT 2017) -----Changed slit width for 02-003 when noticed it was different from the others in that visit. It is now the same as the CCDFLAT and the Wavecal.-1266637304----- Attempting Submission 1 (Tue Jul 18 16:30:31 GMT 2017) -----
HST Phase II Proposal 15076 (GO-15076.apt) successfully submitted.
Receipt: # 15076-1
----- Attempting Submission 2 (Wed Jul 19 13:30:37 GMT 2017) -----The Recent Mass Loss History of the Red Hypergiant VY CMaThe high mass loss episodes observed in evolved massive stars across the HR Diagram remain a mystery. With its very visible discrete ejecta, VY CMa is the perfect star to explore the origin of these events in the evolved yellow and red supergiants. VY CMa's high mass loss rate and its unusual chemistry suggest that it is near the end of the red supergiant stage or possibly in a second short-lived red supergiant stage. Its HST/WFPC2 images are distinguished by prominent large-scale arcs and clumps of knots with minimum masses of 3 x 10^-3 Msun. They were ejected in separate events over the past 800 years in different directions by localized processes from different regions on the star. The physical mechanism that drives these high mass loss events is not understood, but the evidence increasingly suggests that surface activity and magnetic fields are important. The circumstellar ejecta is also filled with numerous small knots and filaments suggesting that this mass loss process has been more frequent. ALMA measurements of the polarization in the dust closest to the star reveals grains aligned by the local magnetic field via a process that must be occurring on relatively short time scales. This material contains dust from the most recent mass loss events. Our proposed observations of the small knots and filaments closest to the star are designed to probe VY CMa's innermost circumstellar ejecta, the frequency of the recent ejections, and set limits on the timescales for the mass loss process.VY CMa is a very luminous red supergiant with a complex extended circumstellar ejecta. The purpose of these observations is to measure the Doppler velocities of several knots close to the star that are very likely from its more recent mass loss events. The knots are distributed around the star less than 0.5 arcsec to the east and west and in two groups or clumps about one arcsec to the south. Some of the knots are about 0.1 arcsec across while others are more diffuse. To cover the knots requires two different slit orientations and therefore two visits.Stellar Physics6falsefalsefalsefalsefalsefalseSUPPORTEDSTARCIRCUMSTELLAR MATTERKNOTM III-INOThis object was generated by the targetselector and retrieved from the SIMBAD database.J2000J2000STARCIRCUMSTELLAR MATTERKNOTNOTwo knots and diffuse ejecta 0.27 arcsec west of the star. Flux is for the brightest knot at 6560A, 50 times fainter than the star.
Offset is given in degrees due to uncertainty whether or not offset in RA is corrected for cos decl.
Offset in RA in sec of time is 0.02s, corrected for cos dec it is 0.018s1.5e-13 ergs/cm^-2/sec^-1/ASTARCIRCUMSTELLAR MATTERKNOTNOA knot 0.55 arcsec west of the star, flux measured at 6560A.
Offset is given in degrees due to uncertainty whether or not offset in RA is corrected for cos decl.
Offset in RA in sec of time is 0.04s, corrected for cos dec it is 0.036s4e-14 ergs/cm^-2/sec^-1/ASTARCIRCUMSTELLAR MATTERKNOTNODiffuse ejecta and knot 0.47 arcsec east of the star, 1000 times fainter than star, flux measured at 6560A.
Offset is given in degrees due to uncertainty whether or not offset in RA is corrected for cos decl.
Offset in RA in sec of time is 0.035s, corrected for cos dec it is 0.0315s4e-15 ergs/cm^-2/sec^-1/ASTARCIRCUMSTELLAR MATTERKNOTNOKnots in the S and SW clumps 0.7 arcsec south of the star. 100 - 300 times fainter than star at 6560A.4e-14 ergs/cm^-2/sec^-1/ASTARCIRCUMSTELLAR MATTERKNOTNOKnots in the S and SW clump 1 arcsec south of the star. 100 -300 times fainter than star at 6560A4e-14 ergs/cm^-2/sec^-1/ASTARCIRCUMSTELLAR MATTERKNOTNOKnots in the S and SW clumps 1.4 arcsec south of the star. 100 - 300 times fainter than star at 6560A.4e-14 ergs/cm^-2/sec^-1/ASTIS/CCDSpectroscopicNoNoG750M7795STIS/CCDSpectroscopicNoNoG750M8561STIS/CCDSpectroscopicNoNoG750M7795STIS/CCDSpectroscopicNoNoG750M8561/data/aps/software/APT/VYCMa/OP-cache/GO-15076-v01.xmlThe scheduling data was generated by CASM 25.2.CASM was run in Phase II mode.(Tic-Visit
:proposal-id 15076
:visit-id "01"
:proposal-version -1
:trans-version "20170613"
:date "17-Jul-2017 15:10:14.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 1
:saa-model "24"
:si-bright-earth-limb-angle 20.0
:data-volume 203184
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 15076
:visit-id "01"
:obset-id "01"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 15076
:visit-id "01"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2856
:al-overhead-at-end 0
:internal-dur-at-end 724
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3225
:pcs-gap 0
)true10VYCMa is extremely bright especially in the red where the detector is sensitve. The ETC for the acquisition with the mirror and F25ND3 gave a S/N of 100 with a 0.3 sec exposure time. Time to saturation is 9.8s. We have observed eta Car numerous times with successful acquisitions using very short integration times like this. You can adjust the integration time if you think it necessary.A precise peakup is required because we will be offsetting to nearby kots and filaments within 1 arsec of the star.
The apparent position of the star is wavelength dependent. For that reason we are doing the peakup at one of the wavelengths where we will be observing, ~ 8500A. We chose this tilt because the spectrum is continuum with some absorption lines. The 7795 tilt is dominated by VERY strong emission of K I. The ETC for spectroscopy with the 52 x 0.1 slit and the 8561 tilt gives a S/N of 56 with a 0.5 sec integration time. Saturation is at 15 sec. The flux of VY CMa at ~8500A is 1.18e-11 erg/s/cm2/A based on its SED. You can adjust this time if necessary.Very short exposure on central star VY CMawavelength calibration for 8561ATwo bright knots plus fainter ejecta within 0.3 arcsec west of the star.Faint knot and ejecta 0.5 arcsec west of the star.Faint knot and ejecta 0.5 arcsec west of the star..CCDFLAT for 8561Awavelength calibration for 7795AFaint knot and ejecta 0.5 arcsec west of the star.Two bright knots plus fainter ejecta within 0.3 arcsec west of the star.Faint knot and ejecta 0.5 arcsec west of the star.Very short exposure on central star VY CMa at 7795ACCDFLAT for 7795A/data/aps/software/APT/VYCMa/OP-cache/GO-15076-v02.xmlThe scheduling data was generated by CASM 25.2.CASM was run in Phase II mode.(Tic-Visit
:proposal-id 15076
:visit-id "02"
:proposal-version -1
:trans-version "20170613"
:date "19-Jul-2017 08:26:37.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 1
:saa-model "24"
:si-bright-earth-limb-angle 20.0
:data-volume 196160
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 15076
:visit-id "02"
:obset-id "02"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 15076
:visit-id "02"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2840
:al-overhead-at-end 0
:internal-dur-at-end 635
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3225
:pcs-gap 0
)true10VYCMa is extremely bright especially in the red where the detector is sensitve. The ETC for the acquisition with the mirror and F25ND3 gave a S/N of 100 with a 0.3 sec exposure time. Time to saturation is 9.8s. We have observed eta Car numerous times with successful acquisitions using very short integration times like this. You can adjust the integration time if you think it necessary.A precise peakup is required because we will be offsetting to nearby kots and filaments within 1 arsec of the star.
The apparent position of the star is wavelength dependent. For that reason we are doing the peakup at one of the wavelengths where we will be observing, ~ 8500A. We chose this tilt because the spectrum is continuum with some absorption lines. The 7795 tilt is dominated by VERY strong emission of K I. The ETC for spectroscopy with the 52 x 0.1 slit and the 8561 tilt gives a S/N of 56 with a 0.5 sec integration time. Saturation is at 15 sec. The flux of VY CMa at ~8500A is 1.18e-11 erg/s/cm2/A based on its SED. You can adjust this time if necessary.Very short exposure on central star VY CMawavelength calibration for 8561ASeveral knots along slit 0.7 arcsec south of star.Faint knots 1 arcsec south of the star.Faint knots 1.4 arcsec south of the star.CCDFLAT for 8561Awavelength calibration for 7795AFaint knots 1.4 arcsec south of the star.Faint knots 1 arcsec south of the star.Several knots along slit 0.7 arcsec south of star.Very short exposure on central star VY CMa at 7795ACCDFLAT for 7795A