A Protostar


Infant Star’s First StepsThis false color image from the Atacama Large Millimeter/submillimeter Array shows a pair of immense jets of dense gas with near-perfect symmetry radiating from a single source at the center of the picture. They’re coming from an extremely young star—a protostar—that is in the early stages of becoming a star much like the Sun. The baby star, known as CARMA-7, and its jets are located around 1,400 light-years from Earth in the Serpens South star cluster. That dense cluster is home to at least 30 more protostars that are being formed in close proximity to one another.

Image Credit: ESO

A Protostar


Infant Star’s First StepsThis false color image from the Atacama Large Millimeter/submillimeter Array shows a pair of immense jets of dense gas with near-perfect symmetry radiating from a single source at the center of the picture. They’re coming from an extremely young star—a protostar—that is in the early stages of becoming a star much like the Sun. The baby star, known as CARMA-7, and its jets are located around 1,400 light-years from Earth in the Serpens South star cluster. That dense cluster is home to at least 30 more protostars that are being formed in close proximity to one another.

Image Credit: ESO

A Young Protostar


hops383The four infrared images on the left are from instruments at Kitt Peak National Observatory and the Spitzer Space Telescope. They show the outburst of HOPS 383, a young protostar in the Orion star-formation complex. The background image is a wide view of the region taken from a Spitzer false color infrared mosaic. Click the image to embiggen it; depending on your browser, a second click may be worth it.

Image Credit: E. Safron et al.
Background: NASA / JPL / T. Megeath (U-Toledo)

A Hole in the Stars?


LDN 483Some of the stars appear to be missing, but the black gap in this starfield is not really a hole. It’s a region clogged with gas and dust. This dark cloud is called Lynds Dark Nebula 483 0r LDN 483. Clouds such as this are the birthplaces of future stars.

LDN 483 is about 700 light-years away in the constellation of Serpens (The Serpent). The cloud contains enough dusty material to completely block the visible light from background stars. Such a dense molecular cloud qualifies as a dark nebulae because of this obscuring property. One might think that the starless nature of a cloud like LDN 483 would suggest that it’s not a place where stars can take root and grow. The opposite is true: dark nebulae offer the most fertile environments for eventual star formation.

Studies of star formation in LDN 483 have discovered some of the youngest observable kinds of baby stars hidden in LDN 483. These gestating stars can be thought of as still being in the womb, having not yet been born as immature stars. In this first stage of stellar development, the star-to-be is just a clump of gas and dust contracting under the force of gravity within the surrounding molecular cloud. The protostar is still quite cool. At about -250°C they are colder than liquid oxygen on the Earth’s surface, and they “shine” only in long-wavelength submillimetrer light. Still, temperature and pressure are beginning to increase in the fledgling star’s core.

This earliest period of star growth lasts for a few thousands of years, an very short amount of time in astronomical terms.Stars typically live for millions or billions of years. Over the course of several million years, the protostar will grow warmer and denser. Its emission will increase, graduating from mainly cold, far-infrared light to near-infrared and finally to visible light. The once-dim protostar will have then become a fully luminous star.

As more and more stars emerge from LDN 483, the dark nebula will disperse and lose its opacity. Finally, the missing background stars that are currently hidden will then come into view, but they will be outshone by the bright young-born stars in the cloud.

Image Credit: ESO

Spitzer’s Orion


orion_spitzerR600hThe Orion Nebula is a stellar nursery 1,500 light-years from here. This false-color infrared view is about 40 light-years across and was assembled using data from the Spitzer Space Telescope. Looking at the nebula in visible light shows many newly-formed stars. This infrared image also shows the nebula’s many protostars still in the process of formation. They show up in the red areas of the image. One of the red spots along the dark dusty filament to the left is and odd protostar cataloged as HOPS 68. It wasrecently found to have crystals of the silicate mineral olivine within its protostellar envelope.

Image Credit: NASA

Cosmic Caterpillar


hubble-caterpillar_0This light-year-long stream of interstellar gas and dust sorta/kinda resembles a caterpillar. Harsh winds from extremely bright stars are blasting ultraviolet radiation at a wannabe star and sculpting the gas and dust into its long shape.

65 of the hottest, brightest known stars, classified as O-type stars are located 15 light-years away from the caterpillar, off the right edge of the image. Those stars and 500 or so less bright, but still highly luminous, B-type stars make up a group called the Cygnus OB2 association which is thought to have a mass more than 30,000 times that of our Sun.

The caterpillar-shaped knot, called IRAS 20324+4057, is a protostar in a very early stage of development. It’s still collecting material from the surrounding envelope of gas, but the envelope is being eroded by the radiation from Cygnus OB2. Protostars in this region should eventually become young stars with masses from one to ten times that of our Sun. However, if the eroding radiation from the nearby bright stars destroys the gas envelope before the protostars finish collecting mass, their their growth is stunted. Spectroscopic observations of the central star within IRAS 20324+4057 show that it is still collecting material quite heavily from its outer envelope, trying to bulk up.

Image Credit: NASA