The Wisconsin H-Alpha Mapper (WHAM) is a custom-built

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...

operated by the

University of Wisconsin–Madison A university () is an educational institution, institution of higher education, higher (or Tertiary education, tertiary) education and research which awards academic degrees in several Discipline (academia), academic disciplines. Universities ty ...

, used to study the

Hydrogen-alpha H-alpha (Hα) is a specific deep-red visible spectral line in the Balmer series with a wavelength of 656.28 nm in air and 656.46 nm in vacuum; it occurs when a hydrogen electron falls from its third to second lowest energy level. H-alpha ...

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

s of the warm ionized medium. It is a tenant telescope at the

Cerro Tololo Inter-American Observatory The Cerro Tololo Inter-American Observatory (CTIO) is an astronomical observatory located on Cerro Tololo in the Coquimbo Region of northern Chile, with additional facilities located on Cerro Pachón about to the southeast. It is approximately ...

(CTIO), in the

Coquimbo Region The Coquimbo Region ( es, Región de Coquimbo, ) is one of Chile's 16 regions (first order administrative divisions). It is bordered by Atacama to the north, Valparaíso to the south, Argentina to the east, and the Pacific Ocean to the west. ...

of northern

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

History

First interest in the ionised

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...

of the

interstellar medium In astronomy, the interstellar medium is the matter and radiation that exist in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstella ...

came when Ron Reynolds pointed a spectrometer through a makeshift observing portal in an office of the University of Wisconsin-Madison's Physical Sciences Laboratory during the late 1970s. Reynolds and colleagues, including Matt Haffner, a senior scientist in UW-M's astronomy department, later developed WHAM.WHAM Brings Milky Way's Ionized Hydrogen into Focus
SpaceDaily.com, 2017-04-12 WHAM formally began life at

Kitt Peak National Observatory The Kitt Peak National Observatory (KPNO) is a United States astronomy, astronomical observatory located on Kitt Peak of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono Oʼodham Nation, west-southwest of Tucson, Arizona. With ...

(KPNO) in November 1996, using the flat mirrors of a two axis, all-sky

siderostat A heliostat (from ''helios'', the Greek word for ''sun'', and ''stat'', as in stationary) is a device that includes a mirror, usually a plane mirror, which turns so as to keep reflecting sunlight toward a predetermined target, compensating f ...

passing light horizontally through a 0.6 m diameter, 8.6 m focal length objective lens into a 2.5 m x 2.5 m x 6 m trailer that contained the spectrometer, that used a low noise, high efficiency CCD camera as a multichannel detector behind a pair of diameter Fabry-Perot etalons/spectrometers.The Wisconsin H-Alpha Mapper
R.J. Reynolds et al,

Australian Astronomical Society The Astronomical Society of Australia (ASA) is the professional body representing astronomers in Australia. Established in 1966, it is incorporated in the Australian Capital Territory. Membership of the ASA is open to people "capable of contributi ...

, V15 N1, accessed 13 April 2017 The system was automated, so that the entire WHAM facility, including opening and closing at the beginning and end of the observing night, was operated from a campus office at the

University of Wisconsin A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, t ...

Madison Madison may refer to: People * Madison (name), a given name and a surname * James Madison (1751–1836), fourth president of the United States Place names * Madison, Wisconsin, the state capital of Wisconsin and the largest city known by this ...

. It operated there from 1996 to 2008. In 2009, WHAM was moved from KPNO to CTIO. WHAM's field of view allows a whole sky survey in about 2 years. WHAM mapped the details of the

Reynolds Layer The Reynolds Layer is a layer of ionised hydrogen gas in the plane of the Milky Way. It was named after Ron Reynolds who discovered that there is such gas. The layer is a disk 750,000 light year A light-year, alternatively spelled light year, ...

References

External links

Official website

WHAM publications
*
The Wisconsin H-Alpha Mapper Northern Sky Survey
(2003 report) *
Early Results from the Wisconsin H-Alpha Mapper Southern Sky Survey
(2010 report) * People *
Matt Haffner
- Senior Scientist *
Ron Reynolds
- Emeritus {{Portal bar, Chile, Astronomy, Stars, Spaceflight, Outer space, Solar System, Education, Science University of Wisconsin–Madison Optical telescopes Astronomical observatories in Chile

History

See also

References

External links