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

The difference between the observed → color index of a star and the intrinsic color index corresponding to its → spectral type. It indicates the modification brought to a color index by the → interstellar absorption.

→ color; excess, M.E., from O.Fr., from L. excessus "departure, going beyond," p.p. excedere "to depart, go beyond," from → ex- "out" + cedere "to go, yield."

Fozuni, from afzuni "excess," afzuni kardan "to exceed bounds," → add; → color.

The state or an instance of surpassing usual, proper, or specified limits. → color excess; → infrared excess.

From L. excessus "going beyond bounds," from stem of excedere "to go beyond," from → ex- "out" + cedere "to go, yield;" cf. Gk. hodos "way;" PIE base *ked- "to go, yield."

Fozuni, from afzuni "excess," afzuni kardan "to exceed bounds," from afzudan "to add, increase," from Mid.Pers. abzudan "to increase, grow;" O.Pers. abijav- "to increase, add to, promote," from abi-, aiby- "in addition to; to; against" + root jav- "press forward;" Av. gav- "to hasten, drive;" Sk. jav- "to press forward, impel quickly, excite," javate "hastens."
Ferehbud "excess" (Mid.Pers. frehbūd "excess"), from Mod.Pers. fereh, firih "much; more" + bud "to be." The first component fereh, from Mid.Pers. frây "more, much," from Av. frāyah- "more; too much, very much" (frāyô.humata- "rich in good thoughts"). The second component bud, budan "to be," from Mid.Pers. budan, from O.Pers./Av. bav- "to be; become, take place;" Av. buta- perf. ptcpl. pass., bavaiti "becomes" (cf. Skt. bhavati "becomes, happens," bhavah "becoming; condition, state;" PIE *bheu- "to be, come into being, become;" Gk. phu- "become," phuein "to bring forth, make grow;" L. fui "I was" (perf. tense of esse), futurus "that is to be, future;" Ger. present first and second person sing. bin, bist; E. to be; O.Ir. bi'u "I am;" Lith. bu'ti "to be;" Rus. byt' "to be").

Infrared → emission from a star in excess of that expected from a → blackbody with the temperature corresponding to the temperature of the star.

→ infrared; → excess.

The excess of → neutrons over → protons in an → atomic nucleus: η = (N_n - N_p) / (N_n + N_p).

→ neutron; → excess.

The difference between the sum of the three angles of a → spherical triangle and 180° (π radians).

→ spherical; → excess.

Ultraviolet emission from an object in excess of that expected for a reference. For example, → subdwarf stars show ultraviolet excess with respect to that expected from a star with → solar metallicity at a given → effective temperature. In this case, UV excess results from smaller → line blanketing in → population II stars.

→ ultraviolet; → excess.