Editing Palomar Observatory (section)

==Telescopes and instruments==
[[File:Palomar Observatory.jpg|thumb|Hale telescope dome]]
[[File:Palomar Observatory 2012 09.jpg|thumb|Component of the Hale telescope]]
<!--[[Image:P48 1994 Jean Large.jpg|thumb|right|Astronomer [[Jean Mueller]] posing with the [[Samuel Oschin telescope|Samuel Oschin Telescope (Schmidt Camera)]] ]]-->
* The {{Convert|200|in|m|adj=mid}} [[Hale Telescope]] was first proposed in 1928 and has been operational since 1949. It was the [[List of largest optical reflecting telescopes|largest telescope in the world]] for 26 years.<ref name=HALE>{{cite web |title=Caltech Astronomy – The 200-inch Hale Telescope |url=http://www.astro.caltech.edu/palomar/about/telescopes/hale.html |publisher=Caltech Astronomy |access-date=2014-12-09}}</ref>{{Citation needed|date=April 2023}}
* A {{Convert|60|in|m|adj=mid}} reflecting telescope is located in the Oscar Mayer Building, and operates fully robotically. The telescope became operational in 1970, and was built to increase sky access for Palomar astronomers. Among its notable accomplishments is the discovery of the first [[brown dwarf]].<ref name=60IN>{{cite web |title=Caltech Astronomy – The 60-inch Telescope |url=http://www.astro.caltech.edu/palomar/about/telescopes/60-inch.html |publisher=Caltech Astronomy |access-date=2014-12-09}}</ref> The 60-inch telescope currently{{When|date=May 2024}} hosts the SED Machine [[integral field spectrograph]] instrument used as part of [[Zwicky Transient Facility|ZTF]] transient followup and classification.<ref>{{cite web |title=Welcome to SED Machine's documentation! |url=https://www.astro.caltech.edu/sedm/ |access-date=2020-07-29 |website=sites.astro.caltech.edu}}</ref><ref>{{cite journal|last1=Blagorodnova|first1=Nadejda|date=March 2018|doi=10.1088/1538-3873/aaa53f|title=The SED Machine: A Robotic Spectrograph for Fast Transient Classification|journal=Publications of the Astronomical Society of the Pacific|volume=130|issue=985|page=035003|url=https://ui.adsabs.harvard.edu/abs/2018PASP..130c5003B/abstract|arxiv=1710.02917|bibcode=2018PASP..130c5003B|s2cid=54892690}}</ref>
* The {{Convert|48|in|m|adj=mid}} [[Samuel Oschin telescope]] development began in 1938, and the telescope saw first light in 1948. It was initially called the 48-inch Schmidt, and was dedicated to [[Samuel Oschin]] in 1986.<ref name=SOT>{{cite web |title=Caltech Astronomy – Samuel Oschin Telescope |url=http://www.astro.caltech.edu/palomar/about/telescopes/oschin.html |publisher=Caltech Astronomy |access-date=2014-12-09}}</ref> Among many notable accomplishments, Oschin observations led to the discovery of the important [[dwarf planet]]s [[Eris (dwarf planet)|Eris]] and [[90377 Sedna|Sedna]].<ref name=SOTD>{{cite web |title=Caltech Astronomy – Discoveries from Palomar Observatory's 48-inch Samuel Oschin Telescope |url=http://www.astro.caltech.edu/palomar/about/telescopes/oschin.html#science |publisher=Caltech Astronomy |access-date=2014-12-09}}</ref> Eris's discovery initiated discussions in the international astronomy community that led to [[Pluto]] being re-classified as a [[dwarf planet]] in 2006.  The Oschin presently operates fully robotically and hosts the 570-million-pixel ZTF Camera <ref>{{Cite book |last1=Dekany |first1=Richard |last2=Smith |first2=Roger M. |last3=Belicki |first3=Justin |last4=Delacroix |first4=Alexandre |last5=Duggan |first5=Gina |last6=Feeney |first6=Michael |last7=Hale |first7=David |last8=Kaye |first8=Stephen |last9=Milburn |first9=Jennifer |last10=Murphy |first10=Patrick |last11=Porter |first11=Michael |last12=Reiley |first12=Dan |last13=Riddle |first13=Reed |last14=Rodriguez |first14=Hector |last15=Bellm |first15=Eric |chapter=The Zwicky Transient Facility Camera |editor-first1=Christopher J. |editor-first2=Luc |editor-first3=Hideki |editor-last1=Evans |editor-last2=Simard |editor-last3=Takami |date=2016 |title=Ground-based and Airborne Instrumentation for Astronomy VI |chapter-url=https://authors.library.caltech.edu/74385/1/99085M.pdf |journal=Proceedings of SPIE |volume=9908 |pages=99085M |doi=10.1117/12.2234558|bibcode=2016SPIE.9908E..5MD |s2cid=38035871 }}</ref>—the discovery engine for the [[ZTF]] project.
* The {{Convert|40|in|m|adj=mid}} WINTER (The Wide-field Infrared Transient Explorer) 1x1-degree reflecting robotic telescope has been operational since 2021. It is dedicated to the seeing-limited time domain survey of the infrared (IR) sky, with a particular emphasis on identifying [[r-process]] material in binary neutron star (BNS) merger remnants detected by LIGO. The instrument observes in Y, J, and a short-H (Hs) band tuned to the long-wave cutoff of the [[Indium gallium arsenide|InGaAs]] sensors, covering a wavelength range from 0.9 to 1.7 microns.<ref name=PSPIE>{{cite book |title=Ground-based and Airborne Instrumentation for Astronomy VIII |chapter-url=https://ui.adsabs.harvard.edu/abs/2020SPIE11447E..67F/abstract |bibcode=2020SPIE11447E..67F |access-date=2021-10-18|last1=Frostig |first1=Danielle |last2=Baker |first2=John W. |last3=Brown |first3=Joshua |last4=Burruss |first4=Rick |last5=Clark |first5=Kristin |last6=Fżrész |first6=Gábor |last7=Ganciu |first7=Nicolae |last8=Hinrichsen |first8=Erik |last9=Karambelkar |first9=Viraj R. |last10=Kasliwal |first10=Mansi M. |last11=Lourie |first11=Nathan P. |last12=Malonis |first12=Andrew |last13=Simcoe |first13=Robert A. |last14=Zolkower |first14=Jeffry |chapter=Design requirements for the Wide-field Infrared Transient Explorer (WINTER) |editor1-first=Christopher J |editor1-last=Evans |editor2-first=Julia J |editor2-last=Bryant |editor3-first=Kentaro |editor3-last=Motohara |year=2020 |volume=11447 |page=113 |doi=10.1117/12.2562842 |arxiv=2105.01219 |hdl=1721.1/142211 |isbn=9781510636811 |s2cid=230542025 }}</ref>

===Decommissioned instruments===
* An {{Convert|18|inch|cm|adj=mid}} [[Schmidt camera]] became the first operational telescope at the Palomar in 1936. In the 1930s, [[Fritz Zwicky]] and [[Walter Baade]] advocated adding survey telescopes at Palomar, and the 18-inch was developed to demonstrate the Schmidt concept.  Zwicky used the 18-inch to discover over 100 [[supernovae]] in other galaxies. [[Comet Shoemaker-Levy 9]] was discovered with this instrument in 1993. It has since been decommissioned and is on display at the small museum/visitor center.<ref name=18IN>{{cite web |title=Caltech Astronomy – The 18-inch Schmidt Telescope |url=http://www.astro.caltech.edu/palomar/about/telescopes/decommissioned.html#p18 |publisher=Caltech Astronomy |access-date=2014-12-09}}</ref><ref name=":1">{{Cite web |title=Greenway Visitor Center |url=https://sites.astro.caltech.edu/palomar/visitor/visitorcenter.html |website=sites.astro.caltech.edu}}</ref>
* The [[Palomar Testbed Interferometer]] (PTI) was a multi-telescope instrument that made high-[[Angular resolution|angular-resolution]] measurements of the apparent sizes and relative positions of stars.  The apparent sizes and in some cases shapes of bright stars were measured with PTI, as well as the apparent [[orbits]] of multiple stellar systems. PTI operated from 1995 to 2008.<ref name=PTI>{{cite web |title=Caltech Astronomy – Palomar Testbed Interferometer (PTI) |url=http://www.astro.caltech.edu/palomar/about/telescopes/decommissioned.html#pti |publisher=Caltech Astronomy |access-date=2014-12-09}}</ref>
* The Palomar Planet Search Telescope (PPST), also known as Sleuth, was a {{Convert|10|cm|in|abbr=|adj=mid}} robotic telescope that operated from 2003 until 2008. It was dedicated to the search for planets around other stars using the [[Astronomical transit|transit]] method. It operated in conjunction with telescopes at [[Lowell Observatory]] and in the [[Canary Islands]] as part of the [[Trans-Atlantic Exoplanet Survey]] (TrES).<ref name=PPST>{{cite web |title=Caltech Astronomy – Sleuth: The Palomar Planet Finder |date=30 October 2009 |url=http://palomarskies.blogspot.de/2009/10/goodbye-to-sleuth.html |publisher=Palomar Skies |access-date=2014-12-09}}</ref>