Hydrogen-alpha, typically shortened to H-alpha or Hα, is a deep-red visible spectral line of the hydrogen atom with a wavelength of 656.28 nm in air and...

region of star formation. The star cluster contains the emission-line star LkHα 101, which provides much of the ionizing radiation in the nebula. NGC 1579...

{\displaystyle \ldots } Or, directly again from the derived definition, Hα(Hα) = α(Hα(Hα)). If α expresses a "computational step" computed by αρν for some ρ...

"Improved radial velocity orbit of the young binary brown dwarf candidate Cha Hα 8". Astronomy and Astrophysics. 521 (A24): A24. arXiv:1006.2383. Bibcode:2010A&A...

extremely difficult to observe visually. It can be observed with a Hα filter (isolates the Hα line at 656 nm) or Hβ filter (isolates the Hβ line at 486 nm)...

L.; Madsen, G. J.; Jaehnig, K. P.; Percival, J. W. (2003), "The Wisconsin Hα Mapper Northern Sky Survey", Astrophysical Journal Supplement, 145 (2): 405...

measured to vary by about 10 km/s around a mean of 21.5 km/s. In 1933, the Hα line in Rigel's spectrum was seen to be unusually weak and shifted 0.1 nm...

S2CID 203593955. Stanishev, V.; Zamanov, R.; Tomov, N.; Marziani, P. (2004). "Hα variability of the recurrent nova T Coronae Borealis". Astronomy and Astrophysics...

brightenings in the Sun's photosphere. They are only observed in the wings of the Hα, Hβ, and Hγ hydrogen spectral lines and take place in emerging flux regions...

Scientific Achievement Medal in 1974. In 1956, Henize published the Catalogues of Hα-Emission Stars and Nebulae in the Magellanic Clouds. The paper references...