### star:

Asterism
* are celestial objects
  - familiar, easily recognized groups of stars
  - groups of stars that make a shape or form of something
  - informal yet distinctive groupings of stars
  - natural objects
  - prominent groups of bright stars to which the eye is drawn
* is caused by the presence of more than one chromophore
  - possible in aqua producing either cats-eye or even star stones
  - the more general term, referring to any identified pattern of stars
* range from the large and obvious to the small, and even telescopic.

B star
* are next to O stars, and thus fairly hot relative to other spectral types.
* have lines produced by helium prominent in their spectra.
* show relatively weak optical spectral lines of hydrogen because b.

Bigger star
* are brighter than smaller stars.
* form more quickly.
* fuse hydrogen to helium faster and live shorter lives.

### star:

Binary
* Binaries are electrical creatures that spend their entire life inside the computer
  - pictures, audio files, movies, or anything other than a plain text e-mail
  - containing two neutron stars are observed to shrink as gravitational waves are emitted
  - lie in different distances
  - refer to non-text files, i.e. applications, images, etc
  - rejuvenate the spectrum of the stellar aggregate
  - require large quantities of disk space
  - take up disproportionate amounts of bandwidth
* Some binaries are too close to see visually but can be discovered by red shifts in their spectra.
+ Binary star, System properties, Detached binaries
  * Most binaries are 'detached binaries'. Except for their gravitational pull on one another, they have no effect on each other.

### star:

Binary star
* Some binary stars appear to be variable stars.
* appear as red point of light below.
* are a pair of stars that orbit each other attaching themselves by a common point
  - popular in science fiction
  - primordial formed at the birth of the two stars
  - twins in the sense that they formed together out of the same interstellar cloud
* are two stars grouped together that appear to be one star
  - orbiting a common center of mass
  - that orbit around a common center of mass
  - very close together and orbiting each other
  - very useful tools in the study of the properties of stars
* comprise about half the solar systems in our galaxy.
* consist of a pair of stars orbiting a common central point
  - two stars in orbit around another and make up most of the stars in the sky
* form a large part of our known universe.
* orbit each other around their common center of mass
* provide astronomers with their primary method for measuring stellar a. luminosity.
* settle into a gravitational dance around a common point in space.
* spiral together and merge.
* vary because of their orbital motion and eclipses.

### star | binary:

Eclipsing binary
* All eclipsing binaries are also spectroscopic binaries.
* Most eclipsing binaries have periods in terms of days.

### star | binary:

Spectroscopic binary
* Some spectroscopic binaries have an orbit that is edge-on to Earth.
* Spectroscopic binaries appear close even when viewed through a telescope.
* Spectroscopic binaries are too far away to see the individual stars
  - two stars that seem to be one
  - is when two sets of spectral lines are doppler shifted due to orbital motion
+ Binary star, Eclipsing binaries
  * Some spectroscopic binaries have an orbit that is edge-on to Earth. When this happens, the stars will take turns passing in front of and eclipsing the partner star, in what is called an 'eclipsing binary'. In this case, the amount of light we see from the double dims slightly during the time one star is in front of the other.