Fine Guidance Sensor 2010 HST Calibration Work Shop Ed Nelan Barbara McArthur STScI

Fine Guidance Sensor 2010 HST Calibration Work Shop Ed Nelan Barbara McArthur STScI Linda Reed, Art Bradley, Mike Wenz, Ed Kimmer, Matt Lallo, Merle Reinhart, & The Guide Star Acquisition Working Group

UDF Field guide stars

Hubble Ultra Deep Field 412 orbits

20 years of HST Focal Plane

FGS2r2: FGS2r was replaced due to failing LEDs on its star selector servos, which put guide star acquisitions at risk. We now have: FGS3 (original) FGS2r2 (new) FGS1r (1997)

SM4: commissioning & calibrating FGS2r2 On orbit commissioning of FGS2r2 began ~ 2 weeks after HST was released from Atlantis AMA adjustment FGS-FGS2r2 alignment Photometric sensitivity Long term monitoring of FGS2r2 has been carried out since May geometric distortion alignment in HST focal plane interferometric response. Future calibrations being contemplated.

AMA adjustment: aligning the FGS Koesters Prism with the optical axis of HST: “before” “after”

Alignment of FGS2r2 w.r.t. FGS1r & FGS3 fgs1r fgs3 fgs2r2

FGS2r2 Commissioning May – June 2009 Interferometer optical alignment (AMA) FGS2r2 scale calibration FGS-FGS2r2 focal plane alignment Photometric sensitivity o FGS2r2 geometric distortion calibration Deferred until instrument stablizes on orbit FGS2r2 is routinely used for guiding HST

FGS2r2: monitoring interference fringes FGS2r2 shows little interferometric evolution during first year in orbit. Due to being in a nitrogen purge from 2002 until 2009? Additional adjustment of AMA apparently not needed. Can proceed with 5-orbit geometric distortion calibration.

FGS1r: Science The Space Telescope Astrometry Team, 10/1996.

April, 1990 Space Shuttle Discovery, STS-31 KSC

HST Timeline, 09/2008 – 03/2010 Sept 15/08: NSSC-I FSW upgrade to support SM4 (WFC3 & COS)

HST Timeline, 09/2008 – 03/ 2010 Sept 15/08: NSSC-I FSW upgrade to support SM4 (WFC3 & COS) Sept 15/08: JSC closed for the week due to Hurricane Ike. Rumors warn that SM4 may slip due to Ike

HST Timeline, 09/2008 – 03/ 2010 Sept 15/08: NSSC-I FSW upgrade to support SM4 (WFC3 & COS) Sept 15/08: JSC closed for the week due to Hurricane Ike. Rumors warn that SM4 may slip due to Ike Sept 24/08: NASA announces SM4 launch is Oct 14

HST Timeline, 09/2008 – 03/ 2010 Sept 15/08: NSSC-I FSW upgrade to support SM4 (WFC3 & COS) Sept 15/08: JSC closed for the week due to Hurricane Ike. Rumors warn that SM4 may slip due to Ike Sept 24/08: NASA announces SM4 launch is Oct 14 Sept 28/08: HST safes, CU/SDF side-A fails, FGS1r is only HST science instrument operating.

HST Timeline, 09/2008 – 03/ 2010 Sept 15/08: NSSC-I FSW upgrade to support SM4 (WFC3 & COS) Sept 15/08: JSC closed for the week due to Hurricane Ike. Rumors warn that SM4 may slip due to Ike Sept 24/08: NASA announces SM4 launch is Oct 14 Sept 28/08: HST safes, CU/SDF side-A fails, FGS1r is only HST science instrument operating. Sept 30/08: NASA postpones SM4.

HST Timeline, 09/2008 – 03/ 2010 Sept 15/08: NSSC-I FSW upgrade to support SM4 (WFC3 & COS) Sept 15/08: JSC closed for the week due to Hurricane Ike. Rumors warn that SM4 may slip due to Ike Sept 24/08: NASA announces SM4 launch is Oct 14 Sept 28/08: HST safes, CU/SDF side-A fails, FGS1r is only HST science instrument operating. Sept 30/08: NASA postpones SM4. Oct 15/08: NSSC-I switch to side-B

HST Timeline, 09/2008 – 03/ 2010 Sept 15/08: NSSC-I FSW upgrade to support SM4 (WFC3 & COS) Sept 15/08: JSC closed for the week due to Hurricane Ike. Rumors warn that SM4 may slip due to Ike Sept 24/08: NASA announces SM4 launch is Oct 14 Sept 28/08: HST safes, CU/SDF side-A fails, FGS1r is only HST science instrument operating. Sept 30/08: NASA postpones SM4. Oct 15/08: NSSC-I switch to side-B Oct 16/08: side-B fails returns to operate Oct 29 FGS1r, WFPC2, ACS/SBC only operating instruments until SM4

FGS Timeline 09/2008 – 03/2010 Oct 23/08: Gilliland et al. allocated 175 FGS orbits to collect one trillion photons from HD Transit events: Nov 6 & 7, Dec 19 Asteroseismology: Dec 21- Jan 2 (ten-day campaign) Nov 25/08: Request to re-optimize FGS1r S-curves via AMA submitted to HSTMO and GSFC HST Project. Approved week of 12/01, executed successfully Jan 23,2009 Nov 30/08: 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, 2008 Previous FGS1r OFAD was Dec 2000.

FGS1r S-curves: significant evolution during 1rst 8 yrs on orbit

FGS1r S-curves: then, stability, no further changes

FGS1r S-curves: post AMA adjustment

AMA move impact on FGS1r OFAD Moving FGS1r AMA shifts pickle in HST focal plane (~5”). Four orbits of FGS1r astrometry were acquired after the AMA move to re-calibrate FGS1r-FGS alignment. The relative positions of 16 stars were measured in each orbit. To measure change in distortion, an identical set of data were acquired prior to the AMA move.

AMA move impact on FGS1r OFAD Blue symbols show residuals in fit of star position using two “before” orbits. Red symbols show residuals in fit of star positions using two “after” orbits. residuals ~1.3 mas

AMA move impact on FGS1r OFAD Blue symbols show residuals of star positions “before” AMA move relative to the the stars position measured “after” the AMA move (Blue) residuals ~4 mas

AMA move impact on FGS1r OFAD The difference in the star positions before and after AMA move suggests that the mirror move introduced a radial term in the distortion.

FGS1r 6-orbit “mini-OFAD” executed March 2010 Stars from the 1mas “OFAD catalog” in M35 were observed.

FGS1r OFAD updated using 03/2010 observations: residuals in measured star positions from observations across the AMA move, using the March 2010 OFAD update. residuals ~ 3 mas

updated OFAD + radial term fit to all 8 (4 before + 4 after) plates residuals in measured star positions from observations across the AMA move, using the March 2010 OFAD update w/radial term in solution. residuals ~ 2 mas (we want 1.6 mas)

Need for a radial term may indicate that 2010 OFAD was not quite adequate (TBD) --- may need supplemental visits in December The “real” way to do OFAD (Dec 2000)

WD , the faintest FGS binary Single scan V = 16.1 system pmtxa = 11.3 pmtxb = 8.8 pmtya = 10.1 pmtyb = 13.8 pmtxa_dark = 3.6 pmtxb_dark = 1.6 pmtya_dark = 3.7 pmtyb_dark = 5.9

WD , the faintest FGS binary twenty scans averaged V = 16.1 system

WD , the faintest FGS binary twenty scans averaged, smoothed, and fit to a model V = 16.1 system  M = 0.9 M p = 16.5 M s = 17.4

WD , the faintest FGS binary WD orbit being mapped by FGS1r.

HST has three healthy Fine Guidance Sensors that will serve until the end of the mission.

NIRCam Observation of the HST UDF. l = b = JWST FGS NIR Camera J < 18.5 see poster by Holfeltz et al. A B