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Hubble Space Telescope Primer for Cycle 23 > Chapter 1: Introduction > 1.2 What’s New This Cycle

1.2
The following instruments will be offered in Cycle 23: two cameras on ACS (ACS/WFC and ACS/SBC), COS, FGS, STIS, and WFC3.
Due to heavy demand and the need for scheduling flexibility in Cycle 23, Large GO programs requesting 75 orbits or more must use the shorter orbital visibility values from Table 6.1; this will be enforced for such programs approved for Phase II.
COS/FUV
In early 2015, COS FUV spectra will be moved from the second COS Lifetime Position (LP2) to the third (LP3) in order to ameliorate the continuing effects of gain sag. While the exact change in performance is not yet known, it is anticipated that the typical spectral resolution, , may decline by about 15%. Depending on the details of the LP3 implementation, it is possible that the resolution decline for the COS FUV G140L grating may be somewhat larger. Changes in the instrument performance at LP3 will be fully characterized in 2015, after the move occurs. Resolution values, quoted in Section 4.4, include an approximately 15% resolution degradation. Instrument performance is otherwise expected to be similar to that seen during Cycle 21 and 22.
The move of COS/FUV operations to LP3 required the implementation of a new FUV spectral extraction algorithm. The new algorithm is currently only optimized for spectral extraction of point sources observed through the PSA. FUV spectra of extended sources and FUV spectra obtained through the BOA will be poorly calibrated. As a result, starting in Cycle 23, COS/FUV science observations using the BOA aperture will be offered as an "Available but Unsupported" mode. Likewise, COS/FUV observations of extended sources will also be offered as "Available but Unsupported." Observers should consult the most recent COS-related newsletters and documentation, available at the COS webpage while preparing their Phase I proposals.
STIS
STIS will offer new supported apertures for STIS MAMA spectroscopy in Cycle 23. Three new officially-supported neutral density filtered slits are offered for first-order and echelle observations. These three apertures, 31X0.05NDA, 31X0.05NDB and 31X0.05NDC, provide attenuation factors of 6X, 14X and 33X respectively. For more information on the basic properties of these apertures see the STIS Instrument Handbook Section 13.4.
Hubble Source Catalog
Version 1 of the Hubble Source Catalog (HSC) is scheduled for release in February, 2015. The HSC combines tens of thousands of single visit-based WFC3, ACS, and WFPC2 source lists from the Hubble Legacy Archive (HLA) into a single master catalog with roughly 100 million individual sources, hence providing entry  into the field of database astronomy. Searches that would require  months or years to perform in the past can, in many cases, be done in  seconds with the HSC. This resource may be used to support a wide range of new archival proposals, a few potential examples of which are listed in Section 7.4 (e.g., variability over more than a 20 year lifetime; in many cases, astrometry with better than 10 mas accuracy; cross-matching with a wide variety of catalogs). Currently, a Beta 0.3 version of the HSC is available to support exploratory projects.

Hubble Space Telescope Primer for Cycle 23 > Chapter 1: Introduction > 1.2 What’s New This Cycle

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