VOL 20 ISSUE 03 Space Telescope Science Institute The Cycle 12 Proposal Peer Review M. Meixner ESA,Credit: NASA, the Hubble Helix Nebula Team, NOAO, Rector (NRAO). See page 6 for more information. (STScI), and T.A. Duccio Macchetto, [email protected], Robert Williams, [email protected], & Brett Blacker, [email protected] Overview Ongoing Features of the Hubble Peer Review ith the continuing excellent performance of the major The oversubscription of Hubble observing time and data-reduction instruments on Hubble, the science program of the funds remains high. Evaluating such a large number of proposals has telescope during Cycle 11 has been very productive. At the led to some distinctive procedures followed by the panels in identify same time there is some uncertainty over the timing of the the best proposals. We expect these procedures to apply to future Wnext servicing mission, which will install the new Cosmic Origins proposal cycles, as follows. Spectrograph and Wide Field Camera 3. Cycle 12 observations will begin in Two-tiered TAC. In consultation with the Space Telescope Institute July 2003 on an accelerated timeline in which the Institute has shortened Council, the Director sets aside one third of the available observing the period between proposal submission and observations by four months. time (~1,000 orbits) for large (over 100 orbits) and Hubble Treasury The Institute received 1,046 proposals in late January 2003 in response to proposals, which the TAC evaluates. The remaining two thirds of the Cycle 12 Call for Proposals. This represents an oversubscription in observing time is devoted to smaller programs, which are evaluated 2003 requested orbits by more than 6 to 1, down slightly from the 1,075 exclusively by the individual disciplinary panels. The relevant proposals received in Cycle 11. The full Time Allocation Committee (TAC) and disciplinary panels review the large and Treasury proposals, but the 11 disciplinary panels met in Baltimore in late March to evaluate the multi-disciplinary TAC performs the final assessment. proposals and to recommend programs to the Director for implementation. Twin panels. Except for the solar system panel, each disciplinary As reported in the fall 2002 Newsletter, an external review of the Institute’s panel has one or two ‘mirror’ panels that consider those proposals for TAC process was conducted last summer, which affirmed the basic integrity which its own members may have some conflict of interest. This and effectiveness of the Hubble peer review, but which recommended procedure minimizes loss of expertise in the discussion due to panelists certain changes in Cycle 12. (See http://www.stsci.edu/resources/ recusing themselves from the evaluations. In Cycle 12, the acceptance rate tac_assessment.) Among these changes were a loosening of institutional for proposals with panelist PIs was the same as that for non-panelist PIs. conflict-of-interest rules governing panelists’ review of proposals, the Progressive orbit subsidy. In order to encourage dissemination of reviewer comments to Principal Investigators (PIs) that panels to resist a tendency to favor smaller Continued reflect the panel discussions, and convening an annual workshop to programs because of the greater number of page 3 facilitate broad collaboration on Hubble Treasury proposals. them that can be approved given the limited SUMMER DIRECTOR’S PERSPECTIVE STARS IN ASTRONOMY Steven Beckwith, [email protected] he other day a friend of mine remarked casually, “It seems that all stellar astronomers over the age of 50 have gotten cranky.” We had noticed a certain defensiveness in one of our colleagues who thought his interests had been marginalized among more fashionable topics often featured in the popular press. Stellar astronomy dominated the study of the universe for most of the last 400 years, and astronomers who work on stars are following a rich tradition. But a lot of us got the feeling that stars are well understood and have moved on to more exotic pursuits, leaving the stellar astronomers to rethink that rich tradition. “Stellar” brings to mind “the best and brightest,” and when I talk Bond is using similar techniques to improve our knowledge of binary about astronomers who work on “stars,” visions of Hollywood and all star masses as a check on stellar evolution theory. There has been a its glamour come to mind. Indeed, the importance of stars as a subject problem with some binary star systems whose components appear to for human inquiry is embedded in the language whenever we want to have much different ages from one another when calculated by our describe individual achievement that stands above all the rest. So why standard theory, whereas we expect them to be coeval. Initial are these “stellar astronomers” cranky? observations of Procyon revised the derived masses of the two stars in It cannot be because of any lack of success with the Hubble Space this binary system downward and brought the observations into Telescope. The Cycle 12 TAC rated a stellar proposal, Fritz Benedict’s agreement with theory for the first time. Bond’s team is continuing with (#9879) as its highest priority this year among nearly 1100 observations of several other binary systems. Stellar evolution theory is competitors. Benedict’s team will measure the distances to Cepheid one of the most important advances of 20th century astrophysics, and variables by direct parallax using the Fine Guidance Sensor (FGS1R) on its verification remains an essential underpinning for our field. Hubble; Howard Bond won time for a similar, albeit smaller program to ER 8 is the coolest known white dwarf in the Galaxy and hence the recalibrate the Cepheid zero point luminosity-period (L-p) relationship oldest. It is nearby and moving rapidly, and by chance it will pass following precise measurements of the distances to these important stars. within 50 mas of a background star in 2006 causing an apparent shift Hubble is now the most precise instrument in history for measuring in the center of light by more than 8 mas owing to gravitational lensing the positions of stars, achieving an accuracy of 0.2 milliseconds of of the star by the white dwarf. This shift is easily detectable with arc (mas), about five times better than Hipparcos, the previous FGS1R, allowing Kailash Sahu and his collaborators to measure the state-of-the-art. At that precision, several fundamental problems in mass of ER 8 to better than 5%. Knowing the mass of this cool white astronomy come into reach for the first time. For example, the l dwarf will allow them to set the best lower limit to the age of the argest uncertainty in the distance scale of the universe, expressed Galaxy yet and, by extrapolation, to the universe itself. This measure of through H0, is the zero point calibration of the L-p relation, which universal age is completely independent of the standard methods of Benedict and Bond can improve by a factor of a few to reduce the cosmology and has the potential to either confirm or deny our standard error in our knowedge of H0—and thus the age of the universe. model for the universe. This is not the sort of impact we expect from a 2 DIRECTOR’S PERSPECTIVE device whose main goal is to keep a spacecraft pointed in the right astrometric precision by as much as the Advanced Camera for Surveys direction, but then Hubble continues to show its superlative improved imaging. Servicing Hubble gives us a lot of bang for the buck, capabilities in unlikely areas. and since it takes a lot of bucks to do it, we are pleased to get a Sumner Starrfield and colleagues recently had their image of the correspondingly big bang. peculiar nova V838 Mon on the cover of Nature, an image so Our stellar astronomers have been flying stealthily below our radar spectacular that it could displace the Eagle Nebula as Hubble’s most screens to pick off some of the most important problems in astronomy iconic image in the public’s mind. We already have T-shirts with V838 with Hubble’s unmatched accuracy. The TAC noticed, I noticed, and Mon that are quite popular among the T-shirt wearing crowd. (I am pretty soon, someone in the science media will notice that a field thinking of getting a tie with that image or maybe another hat.) thought by its own practitioners to be less than fashionable is actually The Fine Guidance Sensors don’t get much respect these days, but cutting a wide swath through new territory and giving the more they are quietly providing opportunities to rewrite the textbooks. glamorous folks a run for their money. FGS1R, installed during servicing mission 3a, has improved the So, if you are a stellar astronomer who is feeling cranky, you may want state-of-the-art to such a degree that it opened up a number of new to take heart in the new opportunities offered by Hubble. It is going to research areas, just as all of Hubble’s new instruments have. The Cycle help you rewrite the textbooks as it has with so many other fields. 12 TAC recommended programs using the FGS for 5% of the total I, for one, will be cheering you on. Ω orbits at the same time that WFPC2—the venerable camera that is responsible for 90% of the public and more than 50% of the scientific impact of Hubble—received only 2% of the time. This change once again show how servicing Hubble has expanded the range of its scientific capabilities: FGS1R improved the state-of-the-art for Cycle 12 Review from page 1 observing time, the Institute subsidizes the cost in orbits charged to the panel for moderate proposals (15-100 orbits).