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They're not the only ones.

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NGC 7250 - Irregular Galaxy

In this image, taken by the Hubble Space Telescope, you can see NGC 7250 (LEDA 68535). It is an irregular galaxy (https://goo.gl/Ixntg1), located in the constellation of Lacerta (The Lizard, https://goo.gl/Pn5u3m), about 45 million light-years away from Earth.

The bright star with the pronounced diffraction spikes is named TYC 3203-450-1 and is a foreground star, much closer to us than NGC 7250. This is the reason why it appears so big and bright, outshining the galaxy behind it.

NGC 7250 features multiple areas of ongoing star formation (https://goo.gl/Mn2Zxf). In 2013 it was home to supernova SN 2013dy, a type Ia supernova (https://goo.gl/ZaAL4z). Supernovae of this type are useful to calculate distances in the universe.

NGC 7250 was discovered on November 8th, 1790, by the British astronomer William Herschel (https://goo.gl/E9YsKH).

More information here:
https://www.spacetelescope.org/images/potw1717a/
https://en.wikipedia.org/wiki/NGC_7250

Diffraction spikes

In the image you can see stars with very pronounced spikes in the form of a cross. These spikes are called diffraction spikes and are caused by the struts that support Hubble's secondary mirror (https://goo.gl/zFd42g). The light is being diffracted around those support struts, generating the cross-formed spikes. They are only visible around point sources where a lot of light is concentrated in one small spot. Read more on it here:
https://en.wikipedia.org/wiki/Diffraction_spike

What is a Type Ia supernova?
http://en.wikipedia.org/wiki/Type_Ia_supernova
and more on the formation and the single degenerate (white dwarf's gravity pulls material from a second star) and double degenerate mechanism (merger of two white dwarfs) here:
http://en.wikipedia.org/wiki/Type_Ia_supernova#Formation

Cosmic Distance Ladder

Type Ia supernovae are an important part of establishing distances in the Universe as they serve as a standard candle. They have a consistent absolute magnitude, and so from looking at the apparent magnitude you can calculate the distance. Read more on the cosmic distance ladder here:
https://en.wikipedia.org/wiki/Cosmic_distance_ladder

More information about the cosmic distance ladder here in this video by Fraser Cain: "How Do We Measure Distance In The Universe?"
https://youtu.be/moiSQ-Gc5pg

Image credit: NGC 7250 ESA/Hubble & NASA https://goo.gl/r2mC4Z CC BY 4.0 https://goo.gl/hNRHCd

Thank you for your interest in this Astronomy/Astrophysics collection. Maybe add me on Google+ (+Pierre Markuse) and Twitter (https://twitter.com/Pierre_Markuse) or have a look at the Space/Space Technology collection here: https://goo.gl/5KP0wx

#science #astronomy #ngc7250 #leda68535 #galaxy #irregulargalaxy #supernova #starformation #hubble #hst #space #photography #cosmicdistanceladder
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Saturn Close Up
Diving through the gap between Saturn and it's Rings, Cassini came within ~ 1,900 miles (3,000 km) of Saturn's cloud tops, and within ~ 200 miles (300 km) of the innermost visible edge of the Rings.
The spacecraft survived this daring plunge, returning the closest ever images of inside Saturn's North Polar Hexagon.
Image credit : NASA/JPL-Caltech/SScI.
https://saturn.jpl.nasa.gov/galleries/raw-images/
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27/04/2017
3 Photos - View album

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Composite ultraviolet-visible-infrared image

This picture is a multi-wavelength composite made by seven individual exposures made with the NASA/ESA Hubble Space Telescope. These exposures were taken by the Faint Object Camera (FOC), Wide Field and Planetary Camera 2 (WFPC2), and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS).

This image is issued jointly by NASA and ESA.

Credit:

NASA, ESA, Dan Maoz (Tel-Aviv University, Israel, and Columbia University, USA)
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Super-rich Galactic Cluster

This new image from the NASA/ESA Hubble Space Telescope shows the super-rich galaxy cluster Abell 1413. Located between the constellations of Leo (The Lion) and Coma Berenices, the cluster is over 2 billion light-years from Earth. This image is dominated by a large and highly elliptical galaxy called MCG+04-28-097, with a halo of stars extending for more than 6.5 million light-years.

Abell 1413 is part of the Abell catalogue, a collection of over 4000 rich clusters of galaxies fairly close to Earth — at least from a cosmological perspective — their light took less than 3 billion years to reach us. The clusters are called rich due to the huge number of galaxies they contain. Abell 1413 is observed to contain more than 300 galaxies held together by the immense gravity of the cluster.

The strong interactions between these galaxies cause the material in the cluster to be heated to extremely high temperatures of almost 100 million degrees. Because of this, the cluster emits very strong X-ray radiation.

Visible distortions in the image can be seen in the form of arcs, caused by gravitational lensing [2].

This image was created from optical and near-infrared exposures taken with the Wide Field Channel of Hubble’s Advanced Camera for Surveys (ACS). A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Nick Rose.
Notes

[1] The galaxies at the centre of Abell 1413 are found to be very highly elliptical whereas those at the periphery are more spherical.

[2] Gravitational lensing occurs when the intense gravity of the cluster bends space-time around it, causing a range of bizarre and beautiful optical phenomena for galaxies located in the background.

Credit:

ESA/Hubble & NASA
Acknowledgement: Nick Rose
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Is our civilisation computer simulation of some advanced extraterrestrial civilisations? Have aliens acquired Godly characteristics and power and are no longer interested in having any contact with us? Are aliens in fact Hungarians?
https://niume.com/post/312891
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