Some 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
The star PDS 70 is still in the process of planet formation, This image of the system taken by the Atacama Large Millimeter Array has attracted a lot of interest. It isn’t the large dust ring still undergoing planet formation that’s the main point of interest. It’s not the Jupiter-sized planet PDS 70c (just above 3 o’clock inside the ring) that’s already come together either. It’s the fuzzy dust cloud around that planet that intrigues astronomers. They believe it’s a region of moon formation. The planet may wind up with three of four large moons just like Jupiter’s.
Named for the southern constellation in whose part of the sky most of its galaxies can be found, the Fornax Cluster is one of the closest clusters of galaxies. At an average of 62 million light-years away, it is almost 20 times more distant than the nearby Andromeda Galaxy. Almost every yellow blob in this two-degree-wide image is an elliptical galaxy in the cluster. The barred spiral galaxy NGC 1365 that stands out in the lower right is a member of the cluster.
Not all spiral galaxies are picture-perfect. Messier 96 (aka NGC 3368) is a case in point: its core is off-center, its gas and dust are distributed asymmetrically, and its spiral arms are ill-defined. It’s still pretty.
The odd galaxy next to the bright foreground star in this picture is the Vela ring galaxy, visible as a bright core surrounded by a blue halo. As the name suggests, this ring galaxy is located in the southern constellation of Vela (The Sails). It is notable for its compact core and large circular belt of gas and stars.
