* Astronomy

Blobrana · L

Hen3-1379

Blobrana · L

RE: IRAS 17163-3907

Blobrana · L

Astronomers it seems have an eye for the prosaic when it comes to dreaming up suitable titles to describe both the kit they use and the phenomena they study.
To that end the European Southern Observatory's Very Large Telsecope (soon to be superseded by the even bigger and more powerful Extremely Large Telescope), has been used to take the first pictures of one of the rarest types of star in the Universe - a colossal yellow hypergiant surrounded by a dusty double shell.
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Blobrana · L

Fried Egg Nebula

Astronomers have used ESO's Very Large Telescope to image a colossal star that belongs to one of the rarest classes of stars in the Universe, the yellow hypergiants. The new picture is the best ever taken of a star in this class and shows for the first time a huge dusty double shell surrounding the central hypergiant. The star and its shells resemble an egg white around a yolky centre, leading the astronomers to nickname the object the Fried Egg Nebula.
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Blobrana · L

Astronomers observe 'Fried Egg Nebula' in infrared sky

The observations of the star and the discovery of its surrounding shells were made using the VISIR infrared camera on the VLT. The pictures are the first of this object to clearly show the material around it and reveal two almost perfectly spherical shells.
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Blobrana · L

Title: A double detached shell around a post-Red Supergiant: IRAS 17163-3907, the Fried Egg nebula
Authors: E. Lagadec, A.A. Zijlstra, R.D. Oudmaijer, T. Verhoelst, N.L.J. Cox, R. Szczerba, D. Mekarnia, H. van Winckel

We performed a mid-infrared imaging survey of evolved stars in order to study the dust distribution in circumstellar envelopes around these objects and to better understand the mass-loss mechanism responsible for the formation of these envelopes. During this survey, we resolved for the first time the circumstellar environment of IRAS 17163-3907 (hereinafter IRAS17163), which is one of the brightest objects in the mid-infrared sky, but is surprisingly not well studied. Our aim is to determine the evolutionary status of IRAS 17163 and study its circumstellar environment in order to understand its mass-loss history. We obtained diffraction-limited images of IRAS 17163 in the mid-infrared using VISIR on the VLT. Optical spectra of the object allowed us to determine its spectral type and estimate its distance via the presence of diffuse interstellar bands. We show that IRAS 17163 is a Post-Red Supergiant, possibly belonging to the rare class of Yellow Hypergiants, and is very similar to the well studied object IRC +10420. Our mid-infrared images of IRAS 17163 are the first direct images of this bright mid-infrared source. These images clearly show the presence of a double dusty detached shell around the central star, due to successive ejections of material with a timescale of the order of 400 years and a total circumstellar mass larger than 4 solar masses. This indicates that non quiescent mass-loss occurs during this phase of stellar evolution.

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Blobrana · L

Fried Egg Nebula

Using the European Southern Observatory's Very Large Telescope (VLT), teams from The University of Manchester, among others, took the new picture showing for the first time a huge dusty double shell surrounding the central hypergiant.
The star and its shells resemble an egg white around a yolky centre, leading the astronomers to nickname the object the Fried Egg Nebula. The international team's results are published in the journal Astronomy & Astrophysics.
The monster star, known to astronomers as IRAS 17163-3907, has a diameter about a thousand times bigger than our Sun. At a distance of about 13 000 light-years from Earth, it is the closest yellow hypergiant found to date and new observations show it shines some 500 000 times more brightly than the Sun.
The observations of the star and the discovery of its surrounding shells were made using the VISIR infrared camera on the VLT. The pictures are the first of this object to clearly show the material around it and reveal two almost perfectly spherical shells.
If the Fried Egg Nebula were placed in the centre of the Solar System, the Earth would lie deep within the star itself and the planet Jupiter would be orbiting just above its surface.
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