This NASA Hubble Space Telescope picture resolves, for the first time, one of the smallest stars in our Milky Way Galaxy. Called Gliese 623b or Gl623b, the diminutive star (right of center) is ten times less massive than the Sun and 60,000 times fainter. (If it were as far away as the Sun, it would be only eight times brighter than the full Moon).
Located 25 light-years away in the constellation Hercules, Gl623b is the smaller component of a double star system, where the separation between the two members is only twice the distance between Earth and the Sun (approximately 200 million miles). The small star completes one orbit about its larger companion every four years.
Gl623b was first detected, indirectly, from astrometric observations that measured the wobble of the primary star due to the gravitational pull of its smaller, unseen companion. However, the star is too dim and too close to its companion star to be seen by ground-based telescopes. Hubble s view is sharp enough to separate the small star from its companion.
The new Hubble observations will allow astronomers to measure the intrinsic brightness and mass of Gl623b. This will lead to a better understanding of the formation and evolution of the smallest stars currently known. Red dwarf stars were once thought to be the most abundant stars in the Milky Way, and thus possibly a solution to the mystery of the Galaxy's "dark matter." However, recent Hubble observations show that these low mass stars are surprisingly rare.
The image was taken in visible light on June 11, 1994, with the European Space Agency s Faint Object Camera.
Credits
C. Barbieri (Univ. of Padua), and NASA/ESA;Investigators: Cesare Barbieri, Gabriele Corrain, Roberto Ragazzoni (Univ. of Padua), Antonella Nota, Guido De Marchi, and Duccio Macchetto (ESA/STScI), and the FOC Instrument Definition Team.
| About The Object | |
|---|---|
| Object Name | Gliese 623b, Gl 623b |
| R.A. Position | 16h 24m 4.0s |
| Dec. Position | 48° 21' 36.0" |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
