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

An orbiting infrared telescope (60 cm mirror) which successfully operated from launch in January 1983 until the supply of coolant ran out in November 1983. It was a collaborative mission between NASA, the Netherlands, and the UK, and mapped 95% of the whole sky in the wavelength bands 12, 25, 60, and 100 microns.

→ infrared; → astronomical; → satellite.

The study of infrared properties of astronomical objects.

→ infrared; → astronomy.

The portion of → electromagnetic radiation from → astrophysical objects in → infrared frequencies.

→ infrared; → emission.

That part of the → electromagnetic radiation lying beyond the red, between the radio and the visible regions of the → electromagnetic spectrum. The wavelengths range from about 0.8 → microns (μm) to about 1000 μm. See also: → near-infrared; → mid-infrared; → far-infrared; → submillimeter radiation.

→ infrared; → radiation.

1) Conditions at an initial time t = t₀ from which a physical system or a given set of mathematical equations evolves.
2) Meteo.: A prescription of the state of a → dynamical system at a specified time; for all subsequent times, the → equation of motion and → boundary conditions determine the state of the system.

→ initial; → condition.

A mathematical expression describing the relative number of stars found in different ranges of mass for a cluster of stars at the time of its formation. It is defined as φ(log M) = dN / dlog M ∝ M ^-Γ, where M is the mass of a star and N is the number of stars in a logarithmic mass interval. The value of the slope found by Salpeter (1955) for → low-mass and → intermediate-mass stars in the → solar neighborhood is Γ = 1.35. The IMF can be expressed also in linear mass units: χ(M) = dN / DM ∝ M ^-α. Note that χ(M) = (1 / M lm 10) φ(log M), and α = Γ + 1. In this formalism the Salpeter slope is α = 2.35. There is a third way for representing the IMF, in which the exponent is x = -α. The IMF is not a single power law over all masses, from → brown dwarfs to → very massive stars (Kroupa, 2002, Science 295, 82). Different slopes have been found for different mass segments, as follows: α = 1.3 for 0.08 ≤ M_solar < 0.5; α = 2.3 for 0.5 ≤ M_solar < 1; α = 2.3 for 1 ≤ M_solar. The IMF at low masses can be fitted by a → lognormal distribution (See Bastian et al., 2010, ARAA 48, 339 and references therein). See also → canonical IMF.

→ initial; → mass; → function.

1) General: The act of injecting. Something that is injected.
2) Physics: The process of introducing electrons or holes into a semiconductor so that their total number exceeds the number present at thermal equilibrium. → hole injection.
3) Math.: A one-to-one → mapping. In other words, a mapping from a → set A onto a set B such that for every element in B there is at the most an element in A.

Verbal noun of → inject.

A → Lindblad resonance expressed by: Ω_p = Ω - κ/m.

→ inner; → Lindblad resonance.

1) Something inscribed; the act of inscribing.
2) The entering of a name on or as if on a list.
3) A historical or religious text carved on stone, brick, or other hard surface.
4) A brief dedication, as of a book or a work of art.

Verbal noun of → inscribe.

The act or process of inseminating.

Verbal noun of → inseminate; → -tion.

A NASA lander designed to study the interior of the planet Mars. It will be a stationary mission, in contrast to NASA's famous Opportunity, Spirit and Curiosity rovers. Staying in place is necessary for its major science goals, which include learning more about the Martian composition, and how tectonically active the red planet is. InSight launched toward Mars on May 5, 2018, landed on Nov. 26, 2018, at the Martian Elysium Planitia, an equatorial zone just south of an ancient volcanic area. InSight will send back data about Mars' interior for about 1 Mars year, or 728 Earth-days. The lander uses sophisticated instruments, to delve deep beneath the surface and seek the fingerprints of the processes that formed the terrestrial planets. It does so by carrying out → seismology, heat flow measurements, and precision tracking.

InSight, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport; → mission.

The amount of radiative energy received from the Sun per unit area per unit time.

Insolation, from L. insolatus p.p. of insolare "to place in the sun," from → in- + sol, → sun, + -ation a suffix denoting action or condition.

Xortâbgiri, from xor "sun," cognate with L. sol→ sun + tâb "light; heat, warmth; illuminating," from tâbidan, tâftan "to shine," tafsidan "to become hot" (Av. tāp-, taf- "to warm up, heat," tafsat "became hot," tāpaiieiti "to create warmth;" cf. Skt. tap- "to spoil, injure, damage; to suffer; to heat, be/become hot," tapati "burns;" L. tepere "to be warm," tepidus "warm;" PIE base *tep- "warm") + giri verbal noun of gereftan "to take, seize" (Mid.Pers. griftan, Av./O.Pers. grab- "to take, seize," cf. Skt. grah-, grabh- "to seize, take," graha "seizing, holding, perceiving," M.L.G. grabben "to grab," from P.Gmc. *grab, E. grab "to take or grasp suddenly;" PIE base *ghrebh- "to seize").

1) The act of inspecting or viewing, especially carefully or critically.
2) Formal or official viewing or examination (Dictionary.com).

Verbal noun of → inspect.

1) Something installed, as machinery or apparatus placed in position or connected for use.
2) The act of installing.
3) The fact of being installed (Dictionary.com).

→ install; → -tion.

The → acceleration of a particle at time t defined by a = lim Δv/Δt = dv/dt. It is the limiting value of Δv/Δt at time t as both Δv and Δt approach zero.

→ instantaneous; → acceleration.

The act of instigating; incitement.

Verbal noun of → instigate.

The mathematical form of the way an instrument affects the input signal.

→ instrumental; → response; → function.

1) The design and use of scientific instruments for detection, measurement, control, computation, and so on.
2) The ensemble of instruments contained in a given machine or system.

From → instrument + -ation a combination of -ate and -ion, used to form verbal nouns.

Sâzâlgari, noun from sâzâlgar, → instrumentalist. Sâzâlgân, with plurality suffix -gân.

1) The act or fact of insulating.
2) Any material used to reduce or prevent the transfer of electricity, heat, cold, or sound.

Verbal noun from → insulate.

An expression of an integer nas the sum of one or more positive integers. The number of different partitions of n is denoted p(n). This function is called the partition function. For example, p(5) = 7, because 5 can be partitioned as: 5 = 5 = 4 + 1 = 3 + 2 = 3 + 1 + 1 = 2 + 2 + 1 = 2 + 1 + 1 + 1 = 1 + 1 + 1 + 1 + 1.

→ partition; → integer.