Dwarf Catalog
Dwarf Catalog
| Group Name | dwarfs |
| Reference | Dwarf Archives
Chris Gelino and Davy Kirkpatrick (IPAC/Caltech), and Adam Burgasser (MIT) Images by Robert Hurt (NASA/IPAC) |
| Prepared by | Brian Abbott (AMNH/Hayden) |
| Labels | Yes |
| Files | dwarfs.speck, dwarfs.label |
| Dependencies | L-dwarf.sgi, T-dwarf.sgi |
| Census | 27 L dwarfs and 53 T dwarfs |
In astronomy, there are dwarf stars; red, white, and brown dwarfs; dwarf novae; and even dwarf galaxies. As you might imagine, astronomers use the term when they refer to the smaller objects in any given class.
For decades it was believed that M stars were the coolest stars in the Universe. M stars, or red dwarfs, make up 70% of the stars in the Galaxy, including our nearest known neighbor, Proxima Centauri. However, a new class of objects, even cooler than M stars, was recently discovered and given the name L dwarf. The L-class dwarfs include normal stars, or red dwarfs, and brown dwarfs, which are not massive enough to ignite the nuclear processes necessary for it to shine as a star.
Also included in this catalog are objects, called T dwarfs. These are even cooler than L dwarfs and are also called brown dwarfs. They resemble large, massive Jupiter-like objects, too large to be planets and too small to be stars. Brown dwarfs are extremely difficult to see, mainly because they are so dim in optical light. However, they appear brighter in infrared light.
Using infrared surveys, such as the Two Micron All Sky Survey (2MASS), astronomers compared data from infrared images to optical images. If an object appeared bright in the infrared, but was dim or nonexistent in optical light, it was targeted for further observation to confirm its identity as a dwarf.
Representing What We Cannot See
In the Digital Universe, we cannot represent these objects accurately since it is not possible to see them with the unaided eye. Instead, we represent them conceptually with over-sized images that astronomers believe resemble these objects. The L dwarfs appear bright red while the T dwarfs are a dimmer red-purple color. It is important to note that the brightness for these objects is grossly exaggerated relative to the stars. Also, their brightness, or size, is not proportional to their intrinsic brightness, but to distance. Of course, if you want to see these dwarfs sized according to their intrinsic luminosity, just type lum lum. To change back to constant luminosity, type lum const.
© 2002-2005 American Museum of Natural History
Last Modified: 2007-12-19 by Brian Abbott