This is a photograph of Gliese 623 taken by the Hubble Space Telescope. This star is one of the smallest stars in the Milky Way.
Click on image for full size
Image from the Hubble Space Telescope, reproduced with permission from AURA/STScI.

Gliese 623b - One of the Smallest Stars in the Galaxy

What's in a Name:The 623rd entry in the Gliese catalog of stars within 25 parsecs of the Sun (originally published in 1969). "B" means the secondary star in a binary system.
Claim to Fame: One of the smallest stars in the Milky Way Galaxy. Part of a double star system. Orbits about its companion in 4 years. Hubble was able to separate the star from its companion for the first time in images shown here.
Type of Star: Red Dwarf Star (Main Sequence). Once thought to be the most abundant type of star in the galaxy but surprisingly found to be very rare. Unsolved Mystery.
How Far Away: 25 light years away
How Big: 1/10 of the sun's mass
How Bright: 1/60,000 of the sun's luminosity (if placed at the sun's location in the solar system would look only eight times brighter than the full moon to us.)
Where to View: Located in the constellation Hercules
When to View: This star not visible without the Hubble. Best to view Hercules from May through October.
Last modified June 15, 2005 by Travis Metcalfe.

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Gamma Ray Bursts - The Most Powerful Objects in the Universe?

Satellites in the 1960's looked for a type of light called Gamma Rays. They found bursts of Gamma Rays coming from outer space! They can't hurt you. They are stopped by the Earth's atmosphere. We have...more

Galaxies - Star Cities

When we look up at the night sky, we notice that there are many stars in our sky. Stars must like to live together in star cities - galaxies. Our city of stars is called the Milky Way, and it is home to...more

Neutron Stars

Neutron Stars form when really big stars die. When such a star runs out of fuel its center begins to collapse under gravity. When the center collapses the entire star collapses. The surface of the star...more

Spiral Galaxies

Spiral galaxies may remind you of a pinwheel that blows in the breeze. Like a pinwheel, a spiral galaxy is rotating, and it has spiral arms. Through a telescope or binoculars,a spiral galaxy may look...more

White Dwarfs

When stars like our own sun die they will become White Dwarfs. As a star like our sun is running out of fuel in its center it grows into a red giant. This will happen to our sun in 5 Billion years. The...more


What's in a Name: Arabic for "head of the demon" Claim to Fame: Represents Medusa's eye in Perseus. A special variable star that "winks" every 3 days. Type of Star: Blue-white Main Sequence Star, and...more

Sirius B - Bizarre White Dwarf Companion of Sirius A

What's in a Name: Nicknamed the "Pup" because it is the companion to Sirius, "the Dog Star" Claim to Fame: Highly compressed white dwarf remnant. Density about 50,000 times that of water. It has approximately...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA