An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The first daylight in the sky before sunrise, equivalent to morning astronomical → twilight; opposed to → dusk.

M.E. dawen (v.), from O.E. dagung, from dagian "to become day," from root of dæg→ day.

Pegâh, from Mid.Pers. pa gâh, literally "soon; near the time (of sunrise)," from pa "to; for; in; on; with; by; according to," O.Pers. upā, Av. upa "toward, with, on, in, in the time of" (cf. Skt. úpa "toward, together with, under, near to, on," Gk. hypo "under, below," L. sub "under," Ger. auf, E. up; PIE *upo "under, up from under, over") + gâh "time," O.Pers. gāθu-, Av. gātav-, gātu- "place, throne, spot" (Skt. gátu- "going, motion; free space for moving; place of abode," PIE *gwem- "to go, come").
Sepidedam, from sepidé "whitish; dawn," from sepid "white" (Mid.Pers. spêt, Av. spita- "white," Skt. śveta- "white," Lith. sviesti "to shine," svaityti "to brighten," P.Gmc. *khwitaz, O.E. hwit, E. white, Ger. weiss, PIE *kwintos/*kwindos "bright") + dam "moment, time; to blow, breathe; smoke" (Mod./Mid.Pers. damidan "to blow, breathe," Av. dāδmainya- "blowing up," Skt. dahm- "to blow," dhámati "blows," Gk. themeros "austere, dark-looking," Lith. dumti "to blow," PIE dhem-/dhemə- "to smoke, to blow").
Bâmdâd, from Mid.Pers. bâmdât, Av. bāmya- "the dawn," from bā- "to shine" (cf. Skt. bhā- "light, brightness," Gk. phainomai "to appear, shine, gleam," Arm. banam "to open, uncover," PIE *bhā- "to shine").

NASA's mission to explore the two largest objects in the → asteroid belt, the asteroid Vesta and the → dawarf planet Ceres, gathering data relating to their composition, internal structure, density and shape. Launched in September 2007, Dawn entered the orbit of → Vesta in July 2011 and spent 16 months there before leaving for → Ceres. It entered Ceres orbit on March 6, 2015. The Dawn spacecraft is made of aluminium and graphite composite, it has a dry mass of 747.1 kg and a mass of 1217.7 kg when fully fuelled prior to launch. The spacecraft is a box-shaped design measuring 1.64m × 1.27m × 1.77m. Dawn ran out of fuel on Nov. 1, 2018, but the spacecraft will continue to orbit Ceres for several decades.

→ dawn; → spacecraft.

An unusually early glow of the horizon near the rising sun during certain times of the year. This early glow does not originate directly from the Sun, but is rather caused by → zodiacal light. It may be mistaken for a sunrise.

→ false; → dawn.