This is the first NASA Herschel Science Center e-newsletter about the Herschel Space Observatory. Information in this newsletter does not replace or supersede information provided by the ESA Herschel Science Center. Here we provide additional information which is expected to be useful to the U.S.-based astronomical community.

1. What is the Herschel Space Observatory?

The Herschel Space Observatory is the fourth 'Cornerstone Mission' of the European Space Agency (ESA) designed to observe the 'cool universe' of forming and evolving galaxies, stars, and planetary systems between 57 and 670 microns.

NASA is making significant contributions to this ESA mission, funding critical elements of two of the science instruments and supporting U.S. investigators on Herschel with data analysis funds and technical support through the NASA Herschel Science Center.

The Observatory will be launched, with Planck Surveyor, on an Ariane-5 from Guiana Space Center in 2008. Science operations, expected to last three years, will be supported from a handful of facilities: a Herschel Science Center, a Mission Operation Center, an Instrument Control Center for each of the three science instruments, and for U.S. observers, a NASA Herschel Science Center.

Herschel contains a 3.5 meter passively cooled Cassegrain telescope. Approximately four months after launch Herschel will arrive at the Sun-Earth L2 point and proceed in a Lissajous orbit around L2 where science operations will begin. [Planck Surveyor will also, independently, travel to and orbit around L2 but in a different orbit than Herschel.] L2 will provide low background levels for the science instruments. It is anticipated that approximately 22 hours per day will be dedicated to scientific operations with the other 2 hours for communications and data transfer with Earth. Approximately 6900 hours of time per year is anticipated to be allocated to science observations.

Herschel will carry three science instruments: PACS, the Photodetector Array Camera and Spectrometer (PI: A. Poglitsch, MPE Garching, Germany), operating between 57 and 210 microns (http://pacs.ster.kuleuven.ac.be/), SPIRE, the Spectral and Photometric Imaging REceiver (PI: M. Griffin, QMW, London, UK), operating between 200 and 670 microns and (http://www.spire.rl.ac.uk/), HIFI, the Heterodyne Instrument for the Far Infrared (PI: Th. de Graauw, SRON, Groningen, Netherlands) operating between 157 and 212 and 240 and 625 microns (http://www.sron.nl/divisions/lea/hifi/). The ideal focal plane temperature for each instrument varies from 1.7K to 10K.

Observation planning and proposal submission for Herschel will be done using HSpot, a Java software package based on the Spitzer Space Telescope software Spot, and, like Spitzer, observations will be specified using Astronomical Observation Templates (AOTs). It is anticipated that HSpot will be released to the astronomical community when the Key Project AO is issued.

A summary of the Herschel Mission can be found in the May 2006 SPIE paper by G. Pilbratt, the Herschel Project Scientist, found here: http://www.rssd.esa.int/Herschel/community_info.shtml

2. Observing Opportunities and Funding for U.S. Scientists

As per standing practice, ESA will open the science opportunities on Herschel to the U.S.-based astronomical community. Approximately two-thirds of the available science time on Herschel will be for Open Time observations. In general, U.S.-based researchers who are awarded time on Herschel will also be awarded data analysis funds to support the analysis of their data.

The first opportunity will be the Key Project Announcement of Opportunity (AO) where both GT and Open Time observers can submit proposals (See section 4 below for timetable). Approximately six months after launch Cycle 1 Open Time proposals will be solicited. It is anticipated that there will be a Cycle 2 opportunity as well. A small fraction (~4%) of Open Time will be set aside for Discretionary Time and Target of Opportunity proposals.

The NHSC will post and advertise these opportunities on our website and via email when they are finalized. All Herschel proposals will be submitted via HSpot to the ESA Herschel Science Center, located at the ESAC outside Madrid, Spain.

3. The NASA Herschel Science Center

In 2002 NASA established the NASA Herschel Science Center (NHSC) at IPAC, Caltech, to provide the U.S. astronomical community with science and observational support throughout all phases of the Herschel Mission. The NHSC is working closely with other Herschel teams in developing observation planning as well as data analysis tools for Herschel. Our web site is: http://www.ipac.caltech.edu/Herschel/

The NHSC is participating in the following activities in preparation for community support:

* Providing core code and support for the development of HSpot.
* Serving of background and confusion estimation tools via HSpot.
* Instrument testing and test data analysis and characterization.
* Developing instrument AOTs and instrument simulators.
* Developing and testing algorithms, and implementing code for data analysis tools, including:
       + map making tools for the instrument imaging modes
       + heterodyne side-band separation and spectral line disentanglement tools
       + spectral defringing tools

4. The Key Project Announcement of Opportunity (AO)

The Key Project AO is expected to be released in February 2007. There will be both GT and Open Time components of this AO, with GT proposals due in April 2007 and Open Time proposals due in Oct 2007, though this schedule is tentative and subject to change. The NHSC website will provdie an up-to-date timeline for calls and due dates. It is expected that the Key Projects will be large spatial or spectral surveys and will be executed early in the science mission.

The Key Projects will be selected and in place before the Cycle 1 Call for GT observers is issued (prior to or approximately at the time of launch). Open Time opportunities, except for Key Projects, will occur *after* launch. The NHSC will post and advertise the Key Project AO when it is issued.

There has already been considerable planning in the GT and OT community on Key Projects. Below is a brief summary. Additional information can be found from the instrument teams presentations at the January 2006 AAS meeting which are found at this URL (under the heading Science Planning near bottom of page): http://www.rssd.esa.int/Herschel/community_info.shtml

PACS Key Projects:

Extragalactic - surveys to the confusion limit of popular fields (GOODS, CDFS, Lockman Hole, COSMOS), clusters and lensing clusters, SEDs of high-z objects, and BAL QSOs, ISM in low metallicity galaxies and star formation in IR bright galaxies.

Galactic - census from prestellar regions to proto-stars to proto-brown dwarfs, AGB stars, post-AGB and PN, and circumstellar envelopes.

Extragalactic surveys coordinated w/PACS (see above) with follow-up spectroscopy, low metallicity dwarf galaxies, ISM in local galaxies.

Galactic - nearby molecular clouds, prestellar cores, high-mass star formation, interstellar dust, debris disk evolution, post-AGB and other evolved stars (SNe) dust production.

Extragalactic - ISM in galactic nuclei and low-metallicity environments

Galactic - AGS envelopes, PPNe, PNe, the warm ISM, star formation regions such as Orion and Sgr B2.

Solar System - Water and chemical studies.

Extra-Hot - An open consortium of investigators, focussing on extragalactic science, pooling resources during all phases of the Open Time program, from proposal planning to reducing the data. Their website is: http://astronomy.sussex.ac.uk/~sjo/extrahot/

Hi-Gal - A survey of the Galactic Plane using PACS and SPIRE, coordinated by Sergio Molinari. Their website is: http://herschel.ifsi-roma.inaf.it/Hi-GAL/index.htm

The NASA Herschel Science Center will host a Observation Planning Workshop in Pasadena California in early 2007 for investigators interested in proposing for Herschel Open Time. We will provide additional information via email and our webpages as the date approaches and plans are finalized.