HERSCHEL
Exploring the formation of galaxies and stars
Découvrir la formation des galaxies et des étoiles
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Elapsed time since launch on 14 May 2009 at 13:12 (UTC).
Welcome to the Herschel Astronomers' website provided by the Herschel Science Centre (HSC) primarily for the scientific community. For additional ESA and external Herschel related web sites see link buttons above and "Useful links".
Herschel was launched on 14 May 2009!
It is the fourth `cornerstone' mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities.
Herschel has been designed to observe the `cool universe'; it is observing the structure formation in the early universe, resolving the far infrared cosmic background, revealing cosmologically evolving AGN/starburst symbiosis and galaxy evolution at the epochs when most stars in the universe were formed, unveiling the physics and chemistry of the interstellar medium and its molecular clouds, the wombs of the stars, and unravelling the mechanisms governing the formation of and evolution of stars and their planetary systems, including our own solar system, putting it into context. In short, Herschel is opening a new window to study how the universe has evolved to become the universe we see today, and how our star the sun, our planet the earth, and we ourselves fit in.
Herschel is now approaching end of helium. No helium will mean no more observations. Herschel will have executed about 35,000 HOTAC approved observations in over 22,000 hours of science observing, amassing over 25,000 hours worth of science data from about 600 observing programmes, including the 42 Key Programmes. Except for observations performed less than 6 months ago all these data are publicly available through the Herschel Science Archive. More than 600 refereed papers have been published so far, for science highlights see News & Press Releases and Latest News.
Herschel has used all its helium!
Herschel has run dry! In the afternoon today (29 April 2013) Herschel ran out of helium! To declare end-of-helium (EoHe) a number of key temperature sensor upper limits had been defined, and with two of them attained, EoHe had formally been reached.
Although Herschel is out of contact with the ground for 21 out of 24 hours, it chose to reach EoHe while in contact and increasing temperatures could be followed in real time during the DTCP.
The cryogenic unit displayed rising temperatures in the helium tank, violating upper limit conditions on one key parameter today at 14:49:23 (UTC), with a second parameter confirming this at 15:20:01 (UTC), thus EoHe was declared.
For more information see the ESA Press Release, the ESA Space Science Portal and the SciTech web releases.
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