Five Busy Months for FGS

Five Busy Months for FGS

STScI/TIPS

01/15/09

Ed Nelan

FGS Timeline, Sept 08 - Jan 09

• Sept 15: NSSC-I FSW upgrade to support SM4 (WFC3 & COS)– During reboot process, FGS1r is only SI available for scheduling (~2 days)



• Sept 15: JSC closed for the week due to Hurricane Ike.– Rumors warn that SM4 may slip due to Ike

• Sept 24: NASA announces SM4 launch is Oct 14

• Sept 24: STScI SMO request PIs of WFPC2 and FGS snaps to swap-in ~50 targets that are observable in the October time frame in the event that SM4 is delayed further. (LRP is depleted of WFC2 GO visits)



• Sept 15: JSC closed for the week due to Hurricane Ike.– Rumors warn that SM4 may slip due to Ike

• Sept 24: NASA announces SM4 launch is Oct 14

• Sept 24: STScI SMO request PIs of WFPC2 and FGS snaps to swap-in ~50 targets that are observable in the October time frame in the event that SM4 is delayed further. (LRP is depleted of WFC2 GO visits)

• Sept 28: Revised FGS Snap proposal 11212 submitted

• Sept 28: HST safes, CU/SDF side-A fails, FGS1r continues to observe

• Sept 30: NASA postpones SM4.


• Oct 9: (Friday) SMO requests an additional 50 FGS targets to populate the October 19 SMS (11212 nearly deleted)– Tony Roman: “if you get it to us by early Tuesday, we’ll make it happen”

– all visits used up in ~10 days (Oct 20-30)




• Oct 15: NSSC-I switch to side-B• Oct 16: side-B fails




• Oct 15: NSSC-I switch to side-B• Oct 16: side-B fails

• Oct 17: SMO requests FGS proposals from UTx and GSU to fill near-term LRP. Suggested size is “50 - 60 orbits”.

• Oct 24: Phase1 & 2 proposals submitted.– UTx proposal has 50 orbits– GSU proposal has 300 orbits (11943 & 11944)


• Oct 23: Gilliland et al. request 175 FGS orbits to collect one trillion photons from HD 17156. Observations to execute:– Transit events: Nov 6 & 7, Dec 19– Asteroseismology: Dec 21- Jan 2 (ten-day campaign)


• Oct 23: Gilliland et al. request 175 FGS orbits to collect one trillion photons from HD 17156. Observations to execute:– Transit events: Nov 6 & 7, Dec 19– Asteroseismology: Dec 21- Jan 2 (ten-day campaign)

• Oct 24: Gilliland proposal accepted– Ron: “Yikes, now we have to do something fast!”– Phase2: extreme orbit crafting by Merle Reinhart (thanks Merle!)

• Oct 29: NSSC-I up and operating on side-B

• Nov 25: Request to re-optimize FGS1r S-curves via AMA submitted to HSTMO and GSFC HST Project.– Approved week of 12/01, to execute Jan 23.


• Nov 30: Phase 2 Proposal “Calibrating FGS1r OFAD, Second Epoch” submitted. 18 orbits.– Needed to execute before December 23 (M35 unavailable afterward), and

before FGS1r AMA re-optimization– Executed successfully, Dec 12 - 20.

FGS1r OFAD, December 2008


• All along, various Cycle 16 & 17 GO FGS proposals have been executing as needed (primarily parallax and exoplanet measurements).

Approximate number of FGS science orbits in last 5 months: 720

< Sep 08 Sep Oct Nov Dec Jan

~170 51 118 122 316 53

FGS Science

• The additional FGS visits solicited by STScI from UTx and GSU had two prime constraints:– Targets schedulable in two-gyro mode in the Dec to March time frame– No long term projects being initiated

• UTx proposal used FGS1r in POS mode to revisit star field that had been observed in the past for positional astrometry (parallaxes)– Some targets hadn’t been observed for years– Some targets had only been observed with FGS3 (not FGS1r)– Late epoch visits will provide extremely accurate proper motion

measurements, which in turn improve parallax (and reflex motion measurement if applicable).

– Observations generally succeeded. Guide star acquisition failures affected one target at a particular Orient.

FGS Science

• GSU proposals used FGS1r in TRANS mode survey targets for binarity, or to observe known binaries to update orbital elements.

• Targets initially were all high mass stars – Proposal 11212 “Filling the Period Gap for Massive Binaries” (PI Gies).– Binary “hit rate” appears to be approximately 30-40%

Proposal 11212FGS1r detection of 0.5” binary

spectral type B1.5III

FGS Science

• GSU proposals used FGS1r in TRANS mode survey targets for binarity, or to observe known binaries to update orbital elements.

• Targets initially were all high mass stars – Proposal 11212 “Filling the Period Gap for Massive Binaries” (PI Gies).– Binary “hit rate” appears to be approximately 30-40%

• Targets in first supplement (proposal 11901) were positive binary detections from 11212 that could schedule in October - December.– 47 targets

• 2nd proposal “Binaries at the Extremes of the H-R Diagram”– Targets include: high mass stars, LBVs, nearby low mass main sequence

stars, cool subdwarfs, and white dwarfs.– Split into two phase2 proposals (11943 & 11944) because APT can’t

handle proposals with more than ~130 visits.

Proposal 11944FGS1r measurement of DD G107-70 orbit

1996

2008

FGS ScienceGilliland proposal 11945:

• “Asteroseismology of Extrasolar Planet Host Stars”– used FGS2 in POS mode to collect high S/N photometry of HD 17156– goal: to collect one trillion photons to search for 10-15 of the highest

amplitude stellar oscillations.– may result in knowledge of the stellar density (~1%) and age (5%).

• HD 17156 hosts a transiting planet. Transit light curve also provides stellar density to ~1%, a good independent check on the asteroseismology.

• Using FGS for this project required calibration of the FGS2 dark counts and the 4 PMT deadtime constants.

• HST project had mild concerns about the PMT life time issues. Target HD 15176 is a V=8.1 star, near the V=8 OLD restriction.– Pre & post checks on Upgren69 were included to verify PMT health.

FGS2r S-curves, before & after 10 day campaign

Upgren69 FGS2r PMT counts decreased by ~0.2%

HD 17156 November Transit, version 1

HD 17156 November Transit version2

FGS1r AMA Adjustment



• Scheduled for week of Jan 19

• Prerequisites:

Determination of AMA move (Goodyear) based upon recently obtained FGS1r S-curves (from large science programs 11212, 11943, 11944)

FGS1r OFAD re-calibration (proposal 11870), Dec 12 - 20, 2009

Preparation of phase2 (11963) proposal to verify OFAD across AMA move, and to provide data to update FGS1r-FGS alignment.

• Uses astrometric field in NGC 5617

Identification of post-AMA move target star to verify FGS1r S-curves are optimal (proposal 11964).

• Verify FGS1r POS mode acquisition after AMA move (11964)

FGS1r-FGS Alignment NGC 5617

FGS1r-FGS Alignment NGC 5617

Post AMA-adjustment verification star, HD 233877

• Standard FGS calibration star known to be single (point source)

• Well isolated, tolerant of FGS1r-FGS alignment errors.

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Five Busy Months for FGS