Astronomy and related astronomical terms

(the science of the celestial bodies: the sun, the moon, and the planets; the stars and galaxies; and all of the other objects in the universe)

The astronomer said,
As he raised his cup,
"Thank heavens my business
Is looking up."
—Ennis Rees, Pun Fun;
Scholastic Book Services; New York; 1965; page 13.
solar wind (s) (noun), solar winds (pl)
The stream of charged particles "blown" by the thermal pressure of the Sun out from its corona, which it cannot retain by gravity: The solar winds are streams of charged atomic particles, mostly protons an electrons, from the Sun's corona, that flow outwards at speeds of between 300 kilometers per second or 200 miles per second and 1,000 kilometers per second or 600 miles per second.

In the vicinity of the Earth, these particles have a velocity of about 300 miles, or 500 kilometers, per second.

solstice (s) (noun), solstices (pl)
1. The moment when the Sun is at its northernmost or southernmost point in the sky, signaling the first day of summer or winter: The summer solstice, when the Sun is farthest north, occurs around June 21 and the winter I>solstice takes place around December 21.

2. The point at which the Sun reaches its greatest positive and negative declinations: The referenced dates, summer solstices and winter solstices, are considered the longest and shortest days of the year, respectively.

space storm (s) (noun), space storms (pl)
When space weather is bad, dangerous particles abound and so space weather has become a general term for the environmental conditions above the Earth's atmosphere: Space storms include protons and ions, known as galactic cosmic rays (GRCs), that rain down at near-light speed from space, and similar particles come in bursts from the Sun, called solar energetic particles (SEPs).
space, outer space (s) (noun) (no pl)
1. The void that exists beyond the earth's atmosphere (no pl): Above 120 kilometers or 75 miles, very little atmosphere remains in outer space, so objects can continue to move quickly without extra energy.

2. The area and atmosphere between the planets: The space around the planets is not entirely empty because it is filled with the tenuous gas of the solar wind as well as particles of dust.

speckle interferometry (s) (noun) (no pl)
A technique for obtaining better images of celestial bodies by taking a series of rapid photographic exposures of the object:

Speckle interferometry enables the effect of scintillation to be minimized.

spectrohelioscope (s) (noun), spectrohelioscopes (pl)
An instrument for studying an image of the sun taken at one particular wavelength, instead of the usual mixture of wavelengths of white light.

The spectrohelioscope is a type of scanning spectroscope that enables an image of the Sun to be formed by examining the Sun in hydrogen light on the Sun's surface and in its atmosphere.

This technique makes the arched prominences and solar flares visible which would otherwise not be seen.

spectrohelioscopy (s) (noun) (no pl)
A process in which the light of the Sun is reflected down the tunnel by a large, driven, flat mirror at the top, open end of the tunnel: The arrangement of the spectrohelioscopy has two advantages in that the only moving part is the flat mirror, rather than the whole massive telescope, and the tunnel can be kept at a uniform temperature and so eliminates any thermal air current that would cause a magnified image to "boil".
spectroscope (s) (noun), spectroscopes (pl)
An instrument that allows quantitative measurements to be made of spectra (splitting up of electromagnetic radiation into constituent wavelengths): A device designed for visual observation of spectra is called a spectroscopeand an instrument that photographs or maps spectra is a "spectrograph".

In optics, the arrangement according to wavelength of visible, ultraviolet, and infrared light.

spectroscopy (s) (noun) (no pl)
In astronomy, the study of determining the composition of celestial objects and for measuring red shifts: Spectroscopy is the investigation of spectral lines from different atoms and molecules which is an important part of studying the chemistry that goes on in stars and in interstellar clouds.

Spectroscopy is one of various techniques for analyzing the energy spectra of beams of particles or for determining mass spectra.

There are many spectroscopic techniques designed for investigating the electromagnetic radiation emitted or absorbed by substances.

Spectroscopy, in various forms, is used for analysis of mixtures, for identifying and determining the structures of chemical compounds, and for investigating energy levels in atoms, ions, and molecules.

spectrum (s) (noun), spectra (pl)
The study of spectral lines from different atoms and molecules which is an important part of studying the chemistry that goes on in stars and in interstellar clouds: A spectrum refers to the splitting up of electromagnetic radiations into the constituent wavelengths.

Atoms can exist in a number of discreet energy levels and they emit or absorb photons when they make transitions from one level to another.

The energies of the photons emitted or absorbed by one atom are different from those of all of the other atoms.

The photon energies are directly related to their frequencies, which set their colors in the spectrum, so by observing the colors of the photons, it is possible to determine which atoms are being observed.

This can be done in a laboratory, and it can also be done with the light reaching us from stars, near or distant, which enables us to identify the atoms that stars are made of.

sporadic (adjective) (not comparable)
Descriptive of a meteor not associated with a major meteor shower: A sporadic star or meteorite is one that is not part of a meteor mass or multitude. .
spring tide (s) (noun), spring tides (pl)
The tide on the Earth's surface when the effect of the Moon and Sun is greatest: Spring tide occurs at new and full moon and when the Moon and Sun are in line.
Spörer's law, Sporer's law (s) (proper noun) (no pl)
A relationship to indicate the frequency of the occurrene of sunspots and their progressive movements to lower latitudes on the Sun: Spörer's law, predicts the variation of sunspot latitudes during a solar cycle and refers to changes in the amount of total solar radiation and its spectral distribution.

The tendency of sunspots to appear at the start of the Sun's eleven-year sunspot cycle at high solar latitudes, and for later sunspots to appear at successively lower solar latitudes, before starting the next cycle at the higher latitudes again.

star (s) (noun), stars (pl)
A body, such as, the Sun, that produces energy by means of nuclear reactions taking place within it: The star is held in a stable state by balancing the outward radiation pressure by the inward gravitational force.

A star is a hot, glowing sphere of gas, usually one that emits energy from nuclear reactions in its core.

A star is a luminous globe of gas, mainly hydrogen and helium, which produces its own heat and light by nuclear reactions.

Although some stars may shine for a very long time, even many billions of years, they are not eternal, and have been found to change in appearance at different stages in their forms.

steady-state theory (s) (proper noun) (no pl)
A theory of the evolution of the universe that states that the universe has always been in the state it is now, which leads to the implication that the universe has no origin, but has always existed: The steady-state theory is a rival theory to that of the Big Bang which claims that the universe has no origin but is expanding because new matter is being created continuously throughout the universe.

The steady-state theory was proposed in 1948 by Austrian-born British cosmologist Hermann Bondi, Austrian-born U.S. astronomer and physicist Thomas Gold, and English astronomer Fred Hoyle, but this concept was challenged in 1965 by the discovery of cosmic background radiation and is now largely rejected by scientists.

Also check out the Index of other Scientific and Technological Topics.