Notice: Due to the conversion of some ACS WFC or HRC observations into

WFPC2, or NICMOS observations after the loss of ACS CCD science

capability in January, there may be an occasional discrepancy between a

proposal's listed (and correct) instrument usage and the abstract that

follows it.

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4411

PERIOD COVERED: UT July 24, 2007 (DOY 205)

OBSERVATIONS SCHEDULED

FGS 11295

Trigonometric Calibration of the Distance Scale for Classical Novae

The distance scale for classical novae is important for understanding

the stellar physics of their thermonuclear runaways, their contribution

to Galactic nucleosynthesis, and their use as extragalactic standard

candles. Although it is known that there is a relationship between their

absolute magnitudes at maximum light and their subsequent rates of

decline--the well-known maximum-magnitude rate-of-decline {MMRD}

relation--it is difficult to set the zero-point for the MMRD because of

the very uncertain distances of Galactic novae. We propose to measure

precise trigonometric parallaxes for the quiescent remnants of the four

nearest classical novae. We will use the Fine Guidance Sensors, which

are proven to be capable of measuring parallaxes with errors of ~0.2

mas, well below what is possible from the ground.

WFPC2 11081

RR Lyrae stars in M31 Globular Clusters: How did the M31 Spiral Galaxy

Form?

The pulsation properties of the RR Lyrae stars in the globular clusters

of the Andromeda galaxy {M31} have the potential to provide essential

insight on the first epoch of the galaxy formation and to trace the

merging episodes that led to the assembly of M31. Their mean periods

along with the cluster metallicities can provide an independent estimate

of the M31 cluster ages and, in turn, of the time scale of the M31 halo

formation, by comparison with their Milky Way counterparts. We will

observe RR Lyrae stars in 6 appropriately selected globular clusters of

M31 using WFPC2 to derive periods, light curves, and physical parameters

of these eyewitnesses of the first epochs of the M31 formation.

WFPC2 11202

The Structure of Early-type Galaxies: 0.1-100 Effective Radii

The structure, formation and evolution of early-type galaxies is still

largely an open problem in cosmology: how does the Universe evolve from

large linear scales dominated by dark matter to the highly non-linear

scales of galaxies, where baryons and dark matter both play important,

interacting, roles? To understand the complex physical processes

involved in their formation scenario, and why they have the tight

scaling relations that we observe today {e.g. the Fundamental Plane}, it

is critically important not only to understand their stellar structure,

but also their dark-matter distribution from the smallest to the largest

scales. Over the last three years the SLACS collaboration has developed

a toolbox to tackle these issues in a unique and encompassing way by

combining new non-parametric strong lensing techniques, stellar

dynamics, and most recently weak gravitational lensing, with

high-quality Hubble Space Telescope imaging and VLT/Keck spectroscopic

data of early-type lens systems. This allows us to break degeneracies

that are inherent to each of these techniques separately and probe the

mass structure of early-type galaxies from 0.1 to 100 effective radii.

The large dynamic range to which lensing is sensitive allows us both to

probe the clumpy substructure of these galaxies, as well as their

low-density outer haloes. These methods have convincingly been

demonstrated, by our team, using smaller pilot-samples of SLACS lens

systems with HST data. In this proposal, we request observing time with

WFPC2 and NICMOS to observe 53 strong lens systems from SLACS, to obtain

complete multi-color imaging for each system. This would bring the total

number of SLACS lens systems to 87 with completed HST imaging and

effectively doubles the known number of galaxy-scale strong lenses. The

deep HST images enable us to fully exploit our new techniques, beat down

low-number statistics, and probe the structure and evolution of early-

type galaxies, not only with a uniform data-set an order of magnitude

larger than what is available now, but also with a fully coherent and

self-consistent methodological approach!

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

of potential non-nominal performance that will be investigated.)

HSTARS: (None)

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL

FGS GSacq 4 4

FGS REacq 11 11

OBAD with Maneuver 30 30

SIGNIFICANT EVENTS: (None)

-Lynn
____________________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP Mission Operations Manager
Lockheed Martin Mission Services (LMMS)

NASA GSFC PH#: 301-286-2876

"The Hubble Space Telescope is the astronomical observatory and key to unlocking the most cosmic mysteries of the past, present and future."    - 7/26/6