Triple Star Systems ftw

[Wanderlust]

A post to spotlight the star System Gliese 667 ABC!! I have an intrest spike in it right now and I want to share it!! (as you may know Alpha Centuari is a triple system as well, though the third star is .2 ly away from the main 2)

I made a short youtube video for my channel.

Gliese A and B go around each other while C goes around A and B. There is a confirmed Super Earth around planet C.





Gliese 667 (also HR 6426 and MLO 4) is a triple star system in the constellation of Scorpius (http://en.wikipedia.org/wiki/Scorpius). The star system lies at a distance of about 6.97 pc (http://en.wikipedia.org/wiki/Parsec) (22.7 ly (http://en.wikipedia.org/wiki/Light_year)). There is a 12th magnitude star close to the other three, but it is not gravitationally bound to the system. To the naked eye, the system appears to be a single faint star of magnitude 5.89.
The system has a relatively high proper motion, exceeding 1 second of arc per year.




The two brightest components, Gl 667 A and Gl 667 B, are separated by an average distance of about 12.6 AU (http://en.wikipedia.org/wiki/Astronomical_unit), but have an eccentric orbit, which takes them as close as about 5 AU, or as far as 20 AU. The orbit takes approximately 42.15 years to complete. The orbital distance translates to an average separation of 1.8" (http://en.wikipedia.org/wiki/Arcsecond).
Gl 667 C orbits further out, between about 56 and 215 AU, equating to an angular separation of about 30".

Gliese 667 A

Gliese 667 A is an orange dwarf star of spectral class (http://en.wikipedia.org/wiki/Stellar_classification) K3V. The star has a lower concentration of heavy elements (metals) than the Sun (http://en.wikipedia.org/wiki/Sun). The star has a mass of around 75% of that of the Sun and a luminosity of around 12 or 13% of that of the Sun. The apparent magnitude (http://en.wikipedia.org/wiki/Apparent_magnitude) is 6.29, giving an absolute magnitude (http://en.wikipedia.org/wiki/Absolute_magnitude) of around 7.07.

Gliese 667 B

Gliese 667 B is an orange dwarf star of spectral class K5V, with a mass of about 65% of that of the Sun, and only about 5% of the Sun's luminosity. The apparent magnitude is 7.24, giving an absolute magnitude (http://en.wikipedia.org/wiki/Absolute_magnitude) of around 8.02.

Gliese 667 C

Gliese 667 C is a red dwarf star of spectral class of M2V. It has a mass of around 38% of that of the Sun and only 0.3% of the Sun's luminosity. The apparent magnitude is 10.25, giving an absolute magnitude of around 11.03.





The Planet around Gliese C


Gliese 667 Cb is an extrasolar planet (http://en.wikipedia.org/wiki/Extrasolar_planet) which orbits Gliese 667 C. This planet has at least 5.7 times the mass of Earth (http://en.wikipedia.org/wiki/Earth) (classifying as super-Earth (http://en.wikipedia.org/wiki/Super-Earth)) and takes a week to orbit the star at a semimajor axis (http://en.wikipedia.org/wiki/Semimajor_axis) of approximately 0.05 AU (http://en.wikipedia.org/wiki/Astronomical_unit). This planet was announced by HARPS (http://en.wikipedia.org/wiki/HARPS) on October 19, 2009, together with 29 other planets. No discovery paper has yet been made available.
http://www.youtube.com/watch?v=joBbHq5KBN4


In this image A and B are in the distnace while C is off screen to the left.



http://www.avatar-forums.com/images/imported/2010/10/317.jpg (http://upload.wikimedia.org/wikipedia/commons/7/72/Gliese_667.jpg)

[stubydub]

o.o sorry but i didnt understand most of that :D

[visualizer]

cool stuff!

[ftxey Keye'ung]

Alpha Centauri is said to be a Binary system but they debate whether or not it's a trinary due to Proxima Centauri.

Proxima Centauri is a flare star that goes through phases where it ejects high levels of radiation, meaning any planets close enough would possibly be iradiated badly :(

Alpha Centauri A+B are said to be possible candiates for planets but due to the nature of the two stars, they theorise that a habitable planet is less likely than a singula star system. Also scientists argue that because there are two stars, the formation of Gas giants as seen in our solar system is less likely.

hmm....TBH they don't have a clue about planets, what to expect about the formation of habitable planets and what types of planets can harbour life....i mean, life can come in many shapes and sizes...not all human.

It's when we get to star systems such a Hexary (dunno if that's the right term?) or star systems that could be out there with 10 stars all orbiting around each other that things become more interesting!

[Dreaming Of Pandora]

It's when we get to star systems such a Hexary (dunno if that's the right term?) or star systems that could be out there with 10 stars all orbiting around each other that things become more interesting!

I believe such systems are classified as Open Star Clusters such as the Pleiades (M45/"Seven Sisters") where ten to hundreds of relatively young stars orbit common centers of gravity. There isn't a star cluster close enough to devote resources to investigate, furthermore, there are much more likely systems closer to home where instrument resolution is far greater.

[ftxey Keye'ung]

I always thought Pleadies was of course a cluster but not a Starsytem....some of them are a few light years apart are they not?

A propper starsystem with planets and 6+ stars would be very strange to see....although the gravitational forces of all 6+ stars would most likely reduce the planets to asteroids of dust belts?

[Dreaming Of Pandora]

Yes that is true but they still do have an orbit around each other, even if they are spread by (around) a light year. If you want something really crazy look up NGC 3603 [YouTube - Hubble Update 10 {2nd of June 2010}: Restless Star Cluster NGC 3603 (http://www.youtube.com/watch?v=r6J8b8bxV4k) (one of my videos - you seem interested :))] It is a star cluster with a majestic nebular cloud virtually blanketing it. At the center of the star cluster there is roughly 10'000 stars packed into a lenght no greater than 3 light years. That's approxiametely 1667 stars existing in an area the size of Saturn's orbit. Now if that isn't wacked out enough I don't know what is. Obviously no life would be present in such an exaggerated system as radiation would vapourise anything. There would also be a lot of stellar cannibalism, which would eventually result in supernovae. Pretty hostile. :)

[Wanderlust]

Yes! I primarily posted this because of that photo! its so good!! Its my desktop now!

[Dreaming Of Pandora]

While we're on the subject of star clusters, here's my newest Hubble Update:

Shows how globular cluster Omega Centauri will behave (in real time) over the next 10'000 years.


http://www.youtube.com/watch?v=GVB9_Uq5QbA