View source for Physics:H band (infrared)

[[File:Atmosfaerisk spredning.png|thumb|Atmospheric windows in the infrared. The H band is the transmission window centred on 1.65 micrometres]]
In [[Astronomy:Infrared astronomy|infrared astronomy]], the '''H band''' refers to an [[Earth:Infrared window|atmospheric transmission window]] centred on 1.65 micrometres with a [[Full width at half maximum]] of 0.35 micrometres<ref name="McClean">Ian McClean, Electronic Imaging in Astronomy, Second Edition, Springer, 2008.</ref> (in the near-infrared).

Save for a limited amount of absorption by water vapor, Earth's atmosphere is highly translucent at the wavelengths covered by the H band.<ref>{{Cite web |title=Infrared Astronomy Optical Filters |url=https://www.andovercorp.com/products/astronomy-filters/infrared-astronomy/ |access-date=2023-04-08 |website=www.andovercorp.com}}</ref> The window is also notably less likely to be contaminated by [[Astronomy:Infrared excess|infrared excess]] than other bands.<ref>{{Cite journal |last1=Hanson |first1=M. M. |last2=Rieke |first2=G. H. |last3=Luhman |first3=K. L. |date=October 1998 |title=Near-infrared H-band features in late O and B stars |url=http://www.scopus.com/inward/record.url?scp=0000455577&partnerID=8YFLogxK |journal=Astronomical Journal |volume=116 |issue=4 |pages=1915–1921 |doi=10.1086/300556 |bibcode=1998AJ....116.1915H |issn=0004-6256|doi-access=free }}</ref>

The band is useful for a range of infrared observations including the imaging of [[Astronomy:Sunspot|sunspot]]s, spectroscopic investigation of late-type stars, and imaging planetary phenomena such as extraterrestrial vortices or volcanic activity in the [[Astronomy:Solar System|solar system]].<ref>{{Cite web |title=InGaAs Cameras for Ground-Based NIR-II/SWIR Astronomy |url=https://www.princetoninstruments.com/learn/astronomy/ground-based-astronomy-nirii-swir |access-date=2023-04-08 |website=Teledyne Princeton Instruments |language=en-US}}</ref> In addition [[Astronomy:Stellar atmosphere|stellar atmosphere]]s are highly transparent in the H band and stellar light in the window originates from deeper in the stellar atmosphere than any other band. It also includes within it access to several sets of [[Physics:Spectral line|spectral line]]s including for [[Chemistry:Carbon monoxide|carbon monoxide]] and [[Chemistry:Cyanide|cyanide]].<ref>{{Cite journal |last1=Wing |first1=Robert |last2=Jørgensen |first2=Uffe |date=December 2003 |title=Stellar Spectra in the H Band |url=https://ui.adsabs.harvard.edu/abs/2003JAVSO..31..110W/abstract |journal=The Journal of the American Association of Variable Star Observers |volume=31 |issue=2 |pages=110–120|bibcode=2003JAVSO..31..110W }}</ref>

== References ==
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[[Category:Electromagnetic spectrum]]
[[Category:Infrared imaging]]



{{Sourceattribution|H band (infrared)}}