An association (astronomy) is a combined or co-added group of astronomical exposures from which cosmic rays have been removed. WFPC2 associations constitute one type of association and are tools in the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...

(HST) archive for using data from the

Wide Field and Planetary Camera 2 The Wide Field and Planetary Camera 2 (WFPC2) is a camera formerly installed on the Hubble Space Telescope. The camera was built by the Jet Propulsion Laboratory and is roughly the size of a baby grand piano. It was installed by servicing missio ...

(WFPC2). Associations were introduced in the HST archive at the beginning of 1998. Since then, astronomers have been able to retrieve on-the-fly re-calibrated co-added WFPC2 images that have already been cleaned of cosmic rays from the

Space Telescope European Coordinating Facility right The Space Telescope – European Coordinating Facility (ST-ECF) was an institution which provided a number of support and service functions primarily for European observers of the NASA/ESA Hubble Space Telescope (HST). It was established in 1 ...

(ST-ECF), the Canadian Astronomy Data Centre (CADC) and

Space Telescope Science Institute The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope (HST), science operations and mission operations center for the James Webb Space Telescope (JWST), and science operations center for th ...

(STScI) archives.

History

The development of a new association pipeline was started in early 1999. Standard cross-correlation techniques were used to measure the offsets among WFPC2 observations belonging to the same proposal and using the same filter. CADC and ST-ECF released the second generation of WFPC2 Associations, known as type B associations in November 2001. Type B associations contain all the exposures that follow the same criterion of association as type A, but do not depend on the availability or the accuracy of the jitter information.

External links

HST Science Archive at STScIHST Science Archive at ST-ECFHST Science Archive at CADC
{{DEFAULTSORT:Association (Astronomy) Astronomical imaging de:Sternassoziation es:Asociación estelar fr:Association stellaire ko:성협 hr:Zvjezdana asocijacija it:Associazione stellare lt:Žvaigždžių asociacija ja:アソシエーション (天文学) pl:Asocjacja gwiazdowa ru:Звёздная ассоциация sk:Hviezdna asociácia fi:Tähtiassosiaatio th:ชุมนุมดาว zh:星协

History

See also

External links