11 Maret 2017

Bintang dan Bintang

the young star V883 Orionis

The brilliant star VFTS 682 in the Large Magellanic Cloud
This view shows part of the very active star-forming region around the Tarantula Nebula in the Large Magellanic Cloud, a small neighbour of the Milky Way. At the exact centre lies the brilliant but isolated star VFTS 682 and to its lower right the very rich star cluster R 136. The origins of VFTS 682 are unclear — was it ejected from R 136 or did it form on its own? The star appears yellow-red in this view, which includes both visible-light and infrared images from the Wide Field Imager at the 2.2-metre MPG/ESO telescope at La Silla and the 4.1-metre infrared VISTA telescope at Paranal, because of the effects of dust.

Artist’s impression of dust formation around a supernova explosion
This artist’s impression shows dust forming in the environment around a supernova explosion. VLT observations have shown that these cosmic dust factories make their grains in a two-stage process, starting soon after the explosion, but continuing long afterwards.

Outbursts from a newborn star
A pair of jets protrude outwards in near-perfect symmetry in this image of Herbig-Haro object (HH) 212, taken by ESO’s already decommissioned Infrared Spectrometer And Array Camera (ISAAC).
The object lies in the constellation of Orion (The Hunter) in a dense molecular star-forming region, not far from the famous Horsehead Nebula. In regions like this, clouds of dust and gas collapse under the force of gravity, spinning faster and faster and becoming hotter and hotter until a young star ignites at the cloud’s centre. Any leftover material swirling around the newborn protostar comes together to form an accretion disc that will, under the right circumstances, eventually evolve to form the base material for the creation of planets, asteroids and comets.
Although this process is still not fully understood, it is common that a protostar and its accretion disc, as seen here edge-on, are the cause of the jets in this image. The star at the centre of HH 212 is indeed a very young star, at only a few thousand years old. Its jets are remarkably symmetric, with several knots appearing at relatively stable intervals. This stability suggests that the jet pulses vary quite regularly, and over a short timescale — maybe even as short as 30 years! Further out from the centre, large bow shocks spread out into interstellar space, caused by ejected gas colliding with dust and gas at speeds of several hundred kilometres per second.

A cosmic flame
Sparkling at the edge of a giant cloud of gas and dust, the Flame Nebula, also referred to as NGC 2024, is in fact the hideout of a cluster of young, blue, massive stars, whose light sets the gas ablaze. Located 1,300 light-years away towards the constellation of Orion, the nebula owes its typical colour to the glow of hydrogen atoms, heated by the stars. The latter are obscured by a dark, forked dusty structure in the centre of the image and are only revealed by infrared observations.
This image is based on data acquired with the 1.5-metre Danish telescope at ESO’s La Silla Observatory in Chile, combining three exposures in the filters B (40 seconds), V (80 seconds) and R (40 seconds).

Infrared view of the Rho Ophiuchi star-forming region
This image shows the Rho Ophiuchi star-forming region in infrared light, as seen by NASA’s Wide-field Infrared Explorer (WISE). Blue and cyan represent light emitted at wavelengths of 3.4 and 4.6 micrometres, which is predominantly from stars. Green and red represent light from 12 and 22 micrometres, respectively, which is mostly emitted by dust.

Sumber : ESO

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