Status Report

NASA Hubble Space Telescope Daily Report #4733

By SpaceRef Editor
November 7, 2008
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Continuing to collect World Class Science

PERIOD COVERED: 5am November 6 – 5am November 7, 2008 (DOY 311/1000z-312/1000z)



FGS 11212

Filling the Period Gap for Massive Binaries

The current census of binaries among the massive O-type stars is seriously incomplete for systems in the period range from years to millennia because the radial velocity variations are too small and the angular separations too close for easy detection. Here we propose to discover binaries in this observational gap through a Faint Guidance Sensor SNAP survey of relatively bright targets listed in the Galactic O Star Catalog. Our primary goal is to determine the binary frequency among those in the cluster/association, field, and runaway groups. The results will help us assess the role of binaries in massive star formation and in the processes that lead to the ejection of massive stars from their natal clusters. The program will also lead to the identification of new, close binaries that will be targets of long term spectroscopic and high angular resolution observations to determine their masses and distances. The results will also be important for the interpretation of the spectra of suspected and newly identified binary and multiple systems.

FGS 11945

Asteroseismology of Extrasolar Planet Host Stars

Detections of stellar oscillations, although a very demanding task in terms of observing time, offers a return of more accurate knowledge about the structure of stars than can be obtained in any other way. In particular, detecting the 10-15 highest amplitude modes in solar-like stars to signal-to-noise of just a few sigma each allows robust constraints on the stellar density to <1%, and the stellar age to within 5-10% of its main sequence lifetime. Ten day observing runs using the FGS as a photometer on any of the 5 best transiting planet systems would enable these asteroseismology returns. From more precisely observed transit shapes than can be obtained from the ground a completely independent constraint on stellar density to ~1% can be obtained. The long observation sets required for asteroseismology also provide an excellent opportunity of detecting transits from other planets, e.g. hypothesized inner -orbit Hot Earths, should any exist. This is a contingency proposal that could return extremely solid science, with potential for communication as exciting use of a now limited telescope should we find ourselves in the unfortunate situation of having only the FGS available for many months.

WFPC2 11130

AGNs with Intermediate-mass Black Holes: Testing the Black Hole-Bulge Paradigm, Part II

The recent progress in the study of central black holes in galactic nuclei has led to a general consensus that supermassive {10^6-10^9 solar mass} black holes are closely connected with the formation and evolutionary history of large galaxies, especially their bulge component. Two outstanding issues, however, remain unresolved. Can central black holes form in the absence of a bulge? And does the mass function of central black holes extend below 10^6 solar masses? Intermediate-mass black holes {<10^6 solar masses}, if they exist, may offer important clues to the nature of the seeds of supermassive black holes. Using the SDSS, our group has successfully uncovered a new population of AGNs with intermediate-mass black holes that reside in low-luminosity galaxies. However, very little is known about the detailed morphologies or structural parameters of the host galaxies themselves, including the crucial question of whether they have bulges or not. Surprisingly, the majority of the targets of our Cycle 14 pilot program have structural properties similar to dwarf elliptical galaxies. The statistics from this initial study, however, are really too sparse to reach definitive conclusions on this important new class of black holes. We wish to extend this study to a larger sample, by using the Snapshot mode to obtain WFPC2 F814W images from a parent sample of 175 AGNs with intermediate- mass black holes selected from our final SDSS search. We are particularly keen to determine whether the hosts contain bulges, and if so, how the fundamental plane properties of the host depend on the mass of their central black holes. We will also investigate the environment of this unique class of AGNs.


Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)


11568 – GSAcq(1,3,1) failed to RGA Hold on FGS-1

ReAcqs @311/14:20z, 311/15:55z, 311/17:31z and 311/19:07z also failed. Real time OBADs executed with OR #18355-0, in an attempt to save Astrometry Proposal ID #11945, @311/14:35z and 311/14:47z were unsuccessful.


#18355-0 Realtime FHST MAPs @ 311/14:47z


                        SCHEDULED      SUCCESSFUL

FGS GSacq               06                  06
FGS REacq               07                  03
OBAD with Maneuver      12                  12


SpaceRef staff editor.