astronomy

At the center of this reflection nebula is the young star V1331 Cyg. The star is starting to contract to become a main sequence star similar to our Sun. What makes V1331Cyg special is the fact that we look almost exactly at one of its poles. Usually, the view of a young star is obscured by the dust from the circumstellar disc and the envelope that surrounds it. However, with V1331Cyg we are actually looking in the exact direction of a jet driven by the star that is clearing the dust and providing this magnificent view.

Credit: ESA/Hubble, NASA, Karl Stapelfeldt (GSFC), B. Stecklum and A. Choudhary (Thüringer Landessternwarte Tautenburg, Germany)

Thor’s Helmet

This stunning image shows the nebula cataloged as NGC 2359, but more commonly known as Thor’s Helmet. It does bear a striking resemblance to the headpiece worn by the Norse god, right down to the wings. The nebula, roughly 30 light-years across, is located about 15,000 light-years away in the constellation Canis Major.

Powering up this nebula is a Wolf-Rayet (WR) star known as HD 56925. WR stars are hot, massive giants late in their evolutionary cycles. This O-type giant, perhaps 20 times more massive than the Sun, has gone through a rapid loss of mass, casting most of its hydrogen out into space. The powerful stellar winds carrying this material outward shock the surrounding interstellar medium, causing it to glow. The wing structures were likely thrown off earlier by the progenitor star, while the central helmet portion of the nebula is a more recent bubble blown by the O-type blue giant.

The Thor’s Helmet nebula is not immortal. The central Wolf-Rayet star, having jettisoned most of its hydrogen outward, begins to fuse heavier elements, but that fusion process will end at iron. The outward pressure from fusion will cease, and the inward pressure of gravity will crush the star down, creating a supernova explosion. The nebula won’t survive the blast, but perhaps the resulting supernova remnant will take on an interesting shape of its own.

For a larger version of this image, go here:http://bit.ly/1KOMSEu

-JF

Image credit & copyright: Adam Block/Mount Lemmon SkyCenter/University of Arizona

Sources: 1, 2, 3

Today the NASA Dawn spacecraft went into orbit around Ceres, a 600-mile-wide, roughly spherical world. The mission, en route since 2007 driven by a revolutionary ion propulsion system, is managed by the Jet Propulsion Laboratory on behalf of NASA’s Science Mission Directorate. 

Designed to orbit the dwarf planet as it had previously orbited the asteroid Vesta, the mission’s eyes include a camera sensitive to visible light, a spectrometer for observing aspects of visible and infrared light, and another sensitive to gamma rays and neutrons. In addition, information gleaned from navigational data is expected to provide insights into the mass and internal structure of the dwarf planet.

Unlike Vesta, Ceres appears more akin to icy moons orbiting Jovian worlds than it is to terrestrial planets such as Earth. Comparisons between Vesta and Ceres are expected to reveal fundamental insights into how a vast nascent protosolar nebula of gas and dust contracted four and a half billion years ago and evolved into today’s Solar System.

Other important questions relating to the mission include the quest for specifics about a significant mass of water believed to exist beneath Ceres’ surface. Before we knew much about other worlds, Earth was sometimes described as a unique “water planet.” Space age studies show that water is not uncommon in the universe, with substantial amounts in comets, certain asteroids, a number of Jovian planet moons, and interstellar space.

Learn more on the Sky Reporter blog. 

Rosetta has captured yet another phenomenal image of Comet 67P/C-G. The view shows the large lobe of the comet to the upper right, with the small lobe to the lower left and the regions adjacent to the comet’s neck cast in shadow. The curved shape of the outflowing material likely results from a combination of several factors, including the rotation of the comet, differential flows of near-surface gas, and gravitational effects arising due to the uneven shape of the comet. (Credit: ESA/Rosetta)

The Dark River to Antares  : Connecting the Pipe Nebula to the colorful region near bright star Antares is a dark cloud dubbed the Dark River, flowing from the picture’s left edge. Murky looking, the Dark River’s appearance is caused by dust obscuring background starlight, although the dark nebula contains mostly hydrogen and molecular gas. Surrounded by dust, Antares, a red supergiant star, creates an unusual bright yellowish reflection nebula. Above it, bright blue double star Rho Ophiuchi is embedded in one of the more typical bluish reflection nebulae, while red emission nebulae are also scattered around the region. Globular star cluster M4 is just seen above and right of Antares, though it lies far behind the colorful clouds, at a distance of some 7,000 light-years. The Dark River itself is about 500 light years away. The colorful skyscape is a mosaic of telescopic images spanning nearly 10 degrees (20 Full Moons) across the sky in the constellation of the Scorpion (Scorpius). via NASA

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Planet ‘reared’ by four parent stars

Growing up as a planet with more than one parent star has its challenges. Though the planets in our solar system circle just one star—our sun—other more distant planets, called exoplanets, can be reared in families with two or more stars. Researchers wanting to know more about the complex influences of multiple stars on planets have come up with two new case studies: a planet found to have three parents, and another with four.

The discoveries were made using instruments fitted to telescopes at the Palomar Observatory in San Diego: the Robo-AO adaptive optics system, developed by the Inter-University Center for Astronomy and Astrophysics in India and the California Institute of Technology in Pasadena, and the PALM-3000 adaptive optics system, developed by NASA’s Jet Propulsion Laboratory in Pasadena, California, and Caltech.

This is only the second time a planet has been identified in a quadruple star system. While the planet was known before, it was thought to have only three stars, not four. The first four-star planet, KIC 4862625, was discovered in 2013 by citizen scientists using public data from NASA’s Kepler mission.

The latest discovery suggests that planets in quadruple star systems might be less rare than once thought. In fact, recent research has shown that this type of star system, which usually consists of two pairs of twin stars slowly circling each other at great distances, is itself more common than previously believed.

Continue Reading.


Keeping an eye on Antennae

This image shows two large galaxies, NGC 4038 and NGC 4039, during a catastrophic collision. While the two galaxies merge, it is unlikely that individual stars will actually collide – but clouds of gas and dust are often swapped, squashed or pulled. These violent events trigger episodes of star formation.

Spanning about 500,000 light-years, this image also shows new star clusters and the giant tidal streams that give this pair of duelling galaxies their popular name: The Antennae.

Data from several telescopes is combined to create this composite image. A mosaic of 20 panels from the Subaru telescope (8.2m) were blended with a further 75 hours of observations. Together this data represents the deepest, and highest resolution, view of the Antennae galaxies. Near and Far Infrared images from the Hubble Space Telescope were then used to image the core of the colliding galaxies.

-CB

Image Data: Subaru, NAOJ, NASA/ESA/Hubble, R.W. Olsen - Processing: Federico Pelliccia and Rolf Wahl Olsen

More Information: 1, 2