| Harpalyke |
A moon of Jupiter was discovered by Scott Sheppard and team in 2000. Harpalyke is also designated as "Jupiter XXII" and "S/2000 J5". In Greek mythology, Harpalyke was the incestuous daughter of Klymenos, King of Thrace. |
| Harvest Moon |
The name of the Full Moon closest to the Autumnal Equinox (September 23 by "The Maine Rule"). |
| Hay Moon |
The name of the Full Moon usually in July. Specifically the first Full Moon after the Summer Solstice (June 22 by "The Maine Rule"). Sometimes known as the "Buck Moon" or the "Thunder Moon." |
| Hegemone |
A moon of Jupiter was discovered by Scott S. Sheppard and team in 2003. Hegemone is also designated as "Jupiter XXXIX" and "S/2003 J8". In Greek mythology, Hegemone was one of the Graces, and a daughter of Zeus (Jupiter). |
| Helene |
A moon of Saturn was discovered by the P. Laques and J. lecacheus on March 1, 1980. Helene also is designated as "Saturn XII" and "S/1980 S6". The moon was named after Helen of Troy. |
| Helike |
A moon of Jupiter was discovered by Scott S. Sheppard and team in 2003. Helike is also designated as "Jupiter XLV" and "S/2003 J6". In Greek mythology, Helike was one of the nymphs that nurtured Zeus (Jupiter) in his infancy on Crete. |
| Heliometer |
An instrument devised originally for measuring the diameter of the sun; now employed for delicate measurements of the distance and relative direction of two stars too far apart to be easily measured in the field of view of an ordinary telescope. |
| Hercules |
The constellation "The Strong Man" |
| Hermippe |
A moon of Jupiter was discovered by Scott S. Sheppard and team in 2001. Hermippe is also designated as "Jupiter XXX" and "S/2001 J3". In greek mythology, Hermippe was a consort of Zeus and mother of Orchomenus. |
| Himalia |
A moon of Jupiter was discovered by Charles Perrine at the Lick Observatory on December 3, 1904. Himalia is also designated as "Jupiter VI". In Greek mythology, Himalia was a nymph who bore three sons of Zeus. |
| Honey Moon |
The name for the Full Moon closest to the Summer Solstice (June 22 by "The Maine Rule"). Usually in June. |
| Horizon |
When observing the sky, the horizon is the line between earth and sky. The horizon can also be defined as the plane between the zenith and nadir. |
| Horologium |
The constellation "The Clock" |
| Hour Angle |
The Right Ascension setting circle of an equatorial mounting. |
| Hunger Moon |
The name of the Full Moon usually in February. Specifically the second Full Moon after Yule (December 22 by "The Maine Rule"). Sometimes known as the "Snow Moon." |
| Hunters Moon |
The name of the Full Moon after the Harvest Moon. |
| Hydra |
A moon of the planet Pluto, also known as Pluto III. Hydra was discovered by the "Pluto Companion Search Team" in June 2005 in images taken by the Hubble Space telescope. In Greek mythology Hydra was a multi-headed dragon who guarded Pluto's underworld of the dead. |
| Hydra |
The constellation "The Sea Serpent" |
| Hydrogen-Alpha Filters |
A type of Solar Filter System consisting of an Energy Rejection Filter and a tunable bandpass filter. These filter system are used to view details of the Solar chromosphere like Solar Prominences. |
| Hydrogen-Beta (H-Beta) Filter |
A type of nebular filter that isolates the hydrogen-beta line alone. |
| Hydrus |
The constellation "The Water Snake" |
| Hyperion |
A moon of Saturn was discovered by William & George Bond and William Lassell on September 16, 1848. Hyperion also is designated as "Saturn VII". In Greek mythology, Hyperion was a Titan and the 'god of observation'. |
