An Etymological Dictionary of Astronomy and Astrophysics
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A physical upper mass limit near 150 Msun assumed for the stellar → initial mass function (Kroupa et al. 2012, arXiv:1112.3340).

→ canonical; → upper; → limit.

Higher, as in place, position, pitch, or in a scale.

Upper, from → up, → hyper-.

Bâlâ, → up; zabarin, → superior.

The part of the → arm between the → shoulder and the → elbow.

→ upper; → arm.

Bâzu "arm," from Mid.Pers. bâzûk "arm;" Av. bāzu- "arm;" Mod.Pers. bâhu "stick, staff; arm;" cf. Skt. bāhu- "arm, forearm;" Gk. pechys "forearm, arm, ell;" O.H.G. buog "shoulder;" Ger. Bug "shoulder;" Du. boeg; O.E. bôg, bôh "shoulder, bough;" E. bough " a branch of a tree;" PIE *bhaghu- "arm").

The general term applied to the atmosphere above the → troposphere.

→ upper; → atmosphere.

Same as → superior culmination.

→ upper; → culmination.

In atomic physics, an initial energy state in an emission transition.

→ upper; → level.

Of an integral operator, the point at which the integration ends.

→ upper; → limit.

A → main sequence star with a mass above 1.5 Msun. Upper main sequence stars have high central temperatures so that they produce their energy through the → CNO cycle. The outward energy flux is very high and therefore this flux cannot be maintained by → radiative transfer. Thus, upper main sequence stars have → convective cores. Outside the core, there is a → radiative zone. The mass of the convective core gradually diminishes as the hydrogen is consumed. The surface hydrogen is fully ionized and the → opacity is due to → electron scattering The opacity due to electron scattering.

→ upper; → main; → sequence.

The upper part of the Earth's → mantle which begins at the base of the → crust around 35 km and extends downward to about 410 km.

→ upper; → mantle.

Same as → upper mass limit.

→ upper; → mass; → cut-off.

The highest mass range admitted in a star formation model. The high mass end of the → initial mass function. The upper mass limit is a critical parameter in understanding → stellar populations, → star formation, and → massive star feedback in galaxies.

→ upper; → mass; → limit.

The movement of a celestial body across a celestial meridian's upper branch. Same as → upper culmination.

→ upper; → transit.