Starship Asterisk*

http://antwrp.gsfc.nasa.gov/apod/ap040509.html wrote:
Explanation: Why is the sky near Antares and Rho Ophiuchi so colorful? The colors result from a mixture of objects and processes. Fine dust illuminated from the front by starlight produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark. Antares, a red supergiant and one of the brighter stars in the night sky, lights up the yellow-red clouds on the upper left. Rho Ophiuchi lies at the center of the blue nebula on the right. The distant globular cluster M4 is visible just below Antares, and to the left of the red cloud engulfing Sigma Scorpii. These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum.

http://en.wikipedia.org/wiki/Sigma_Scorpii wrote:
<<Sigma Scorpii is a star system in the constellation Scorpius. It has the traditional name Al Niyat (Arabic النياط an-niyāţ meaning "the ARTeries [of the scorpion]"), although this name is sometimes also applied to Tau Scorpii, or to the asterism formed by both Sigma and Tau. Sigma Scorpii is 735 light years from the Sun.

The primary component of the system, Sigma Scorpii A, is classified as a blue-white B-type giant. It is a variable star of the Beta Cephei type. Its apparent brightness varies hardly perceptibly between +2.86 and +2.94 with multiple periods of 0.2468429, 0.239671, and 8.2 days. It is itself an eclipsing binary, and has a nearby O-type companion which makes an orbit once every 33 days.

Orbiting this binary at a separation half an arcsecond, or at least 120 Astronomical Units (AU), four times the Sun–Neptune distance, is the magnitude +5.2 Sigma Scorpii C which has an orbital period of over a hundred years. Even farther out at 20 arcseconds, or more than 4500 AU, is Sigma Scorpii B with a magnitude of +8.7. It is classified as a B9 dwarf.>>

http://en.wikipedia.org/wiki/Tau_Scorpii wrote:
<<Tau Scorpii also has the traditional name Alniyat or Al Niyat, which it shares with σ Scorpii.
{Star at the BOTTOM of http://apod.nasa.gov/apod/ap090708.html }

Tau Scorpii is a blue-white B-type dwarf with an apparent magnitude of +2.82. It is approximately 430 light years from Earth.

Tau Scorpii is a magnetic star whose surface magnetic field was mapped by means of Zeeman-Doppler imaging:

http://antwrp.gsfc.nasa.gov/apod/ap080215.html wrote:
Explanation: Cosmic dust clouds and embedded newborn stars glow at infrared wavelengths in this tantalizing false-color view from the Spitzer Space Telescope. Pictured is of one of the closest star forming regions, part of the Rho Ophiuchi cloud complex some 400 light-years distant near the southern edge of the pronounceable constellation Ophiuchus. The view spans about 5 light-years at that estimated distance. After forming along a large cloud of cold molecular hydrogen gas, newborn stars heat the surrounding dust to produce the infrared glow. An exploration of the region in penetrating infrared light has detected some 300 emerging and newly formed stars whose average age is estimated to be a mere 300,000 years -- extremely young compared to the Sun's age of 5 billion years.

http://news.softpedia.com/news/Rho-Ophiuchi-a-Craddle-for-Young-Stars-78492.shtml wrote:
<<Similarly to most gas clouds in the universe, Rho Oph is mainly composed of molecular hydrogen gas, in which new stars may form. Rho Ophiuchi is one of the closest star-forming nebula to our solar system, lying only 407 light years away, in a region of space located between the Scorpius and Ophiuchus constellations.

Lately, the Spitzer Space Telescope has been able to examine the area in great detail in the X-ray and the infrared spectrums, revealing the presence of about 300 young stars, many less than 300,000 years old, while some stars still exist since the period soon after the birth of the universe, more than 12 billion years ago.

Lori Allen from the Harvard Smithsonian Center for Astronomy says that Rho Oph is the preferred region for astronomical study, especially while investigating star formation, as it is home to some of the youngest stars in the whole universe, that can be observed in their early evolutionary stage, not to mention that Rho Oph is relatively close to Earth, fact that enables very detailed observations that can be correlated to those seen in distant star clusters.



The particular image seen here pictures the most massive of the clouds in the Rho Oph nebula, Lynds 1688, in the infrared spectrum, which can put into evidence, with relative ease, the temperatures of the young stars and the different evolutionary stages which they go through. Some of the youngest ones seem to present accretion disk of matter that could, in theory, create planets. Because they haven't yet had time to clear the whole mass of gas surrounding them, most are embedded into compact gas clouds, represented in red, while old star can be seen as blue in the image.

You can see how the central regions of the nebula appear to have a white color, due to the excess heat generated by the young stars, which is being absorbed by the gas cloud and re-emitted in the form of infrared light. However, the color of the nebula is not dependent only on temperature, but on composition and dust grain size also. Images taken by the Spitzer observatory show how the vast majority of stars are mostly found in filaments of cold, dense gas in the the lower center, left of the nebula.>>

DavidLeodis wrote:I'm unsure which exactly is Rho Ophiuchi in the image.The explanation states "bright blue double star Rho Ophiuchi". If it is that in the large blue nebula then it looks like a group of three stars (one larger than the other two), not two. On looking up information on Rho Ophioiuchi it states it a triple star group.

• ϱ Oph AB (HIP 80473) is a close double star.
  
  ϱ Oph AB (HIP 80473) / ϱ Oph C(HIP 80474) / ϱ Oph D (HIP 80461) is a "triple star group".