Starship Asterisk*

[img3="Credit: ESO; Acknowledgement: Flickr user jbarring"]https://cdn.eso.org/images/large/potw1636a.jpg[/img3][hr][/hr]

The colour blue has many associations — coldness, sadness, serenity. However, the colour holds a completely different meaning for astronomers, as demonstrated by the edge-on spiral galaxy Messier 98.

Messier 98, also known as NGC 4192, is located approximately 50 million light-years away in the constellation of Coma Berenices (Berenice's Hair). In this spectacular image from ESO’s New Technology Telescope (NTT), the galaxy’s perimeter, rippled with gas and dust, is dotted with pockets of blueish light. These are regions filled with very young stars, which are so hot that they glow with a bright blue hue. These young stars are burning at such high temperatures that they are emitting fierce radiation, burning away some of the dense material that surrounds them. In total, Messier 98 is thought to contain one trillion stars!

The NTT is a 3.58-metre telescope at the La Silla Observatory, which pioneered the use of active optics and was the first in the world to have a computer-controlled main mirror.

[img3="Credit: ESA/Hubble & NASA"]https://cdn.spacetelescope.org/archives ... w1636a.jpg[/img3][hr][/hr]

This shot from the NASA/ESA Hubble Space Telescope shows a maelstrom of glowing gas and dark dust within one of the Milky Way’s satellite galaxies, the Large Magellanic Cloud (LMC).

This stormy scene shows a stellar nursery known as N159, an HII region over 150 light-years across. N159 contains many hot young stars. These stars are emitting intense ultraviolet light, which causes nearby hydrogen gas to glow, and torrential stellar winds, which are carving out ridges, arcs, and filaments from the surrounding material.

At the heart of this cosmic cloud lies the Papillon Nebula, a butterfly-shaped region of nebulosity. This small, dense object is classified as a High-Excitation Blob, and is thought to be tightly linked to the early stages of massive star formation.

N159 is located over 160 000 light-years away. It resides just south of the Tarantula Nebula (heic1402), another massive star-forming complex within the LMC. It was previously imaged by Hubble’s Wide Field Planetary Camera 2, which also resolved the Papillon Nebula for the first time.

bystander wrote:Why So Blue? (Messier 98)
ESO Picture of the Week | 2016 Sep 05

[img3="Credit: ESO; Acknowledgement: Flickr user jbarring"]https://cdn.eso.org/images/large/potw1636a.jpg[/img3][hr][/hr]

The colour blue has many associations — coldness, sadness, serenity. However, the colour holds a completely different meaning for astronomers, as demonstrated by the edge-on spiral galaxy Messier 98.

Messier 98, also known as NGC 4192, is located approximately 50 million light-years away in the constellation of Coma Berenices (Berenice's Hair). In this spectacular image from ESO’s New Technology Telescope (NTT), the galaxy’s perimeter, rippled with gas and dust, is dotted with pockets of blueish light. These are regions filled with very young stars, which are so hot that they glow with a bright blue hue. These young stars are burning at such high temperatures that they are emitting fierce radiation, burning away some of the dense material that surrounds them. In total, Messier 98 is thought to contain one trillion stars!

The NTT is a 3.58-metre telescope at the La Silla Observatory, which pioneered the use of active optics and was the first in the world to have a computer-controlled main mirror.

Ann wrote:

bystander wrote:Why So Blue? (Messier 98)
ESO Picture of the Week | 2016 Sep 05

[img3="Credit: ESO; Acknowledgement: Flickr user jbarring"]https://cdn.eso.org/images/large/potw1636a.jpg[/img3][hr][/hr]

The colour blue has many associations — coldness, sadness, serenity. However, the colour holds a completely different meaning for astronomers, as demonstrated by the edge-on spiral galaxy Messier 98.

Messier 98, also known as NGC 4192, is located approximately 50 million light-years away in the constellation of Coma Berenices (Berenice's Hair). In this spectacular image from ESO’s New Technology Telescope (NTT), the galaxy’s perimeter, rippled with gas and dust, is dotted with pockets of blueish light. These are regions filled with very young stars, which are so hot that they glow with a bright blue hue. These young stars are burning at such high temperatures that they are emitting fierce radiation, burning away some of the dense material that surrounds them. In total, Messier 98 is thought to contain one trillion stars!

The NTT is a 3.58-metre telescope at the La Silla Observatory, which pioneered the use of active optics and was the first in the world to have a computer-controlled main mirror.

M98 is not very blue. Its colors are .810 (B-V) and .310 (U-B). Both values are unremarkable. The far infrared magnitude of M98 is 0.2 magnitudes brighter than its B magnitude. That, too, is quite average.

If M98 looks blue in the ESO image, it just means that whoever processed the picture has "turned up" the blue channel. Nothing more.

There are many interestingly blue galaxies out there, but M98 is not one of them.

Ann

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This week’s picture was taken by ESO Photo Ambassador Babak Tafreshi at ESO’s La Silla Observatory. The bright lane of the Milky Way can be seen streaking across the skies above the Chilean Atacama Desert, beneath which sits the New Technology Telescope (NTT), one of the ten active telescopes located at the observatory.

La Silla is the oldest observation site used by ESO — it has been an ESO stronghold since the 1960s. The site houses a number of telescopes, two of which are operated solely by ESO: the aforementioned NTT, the star of this image, and the 3.6-metre ESO telescope.

Joining this duo are many other collaborative telescopes, operated by various ESO Member States — the Swiss 1.2-metre Leonhard Euler Telescope, the Rapid Eye Mount (REM) telescope, the TAROT gamma-ray-burst chaser, the planet-hunting TRAPPIST, the MPG/ESO 2.2-metre telescope, the ESO 1-metre Schmidt telescope, the ESO 1-metre, and the Danish 1.54-metre telescope.

The NTT saw first light in 1989. It was a key player in ESO’s development of active optics, a technique used by astronomers to control the shape of the main mirror and correct for deformations that may affect image quality. Today, active optics is — or will be — used by all major modern telescopes, including ESO’s Very Large Telescope (VLT) and the forthcoming European Extremely Large Telescope (E-ELT). ...

[img3="Credit: ESA/Hubble & NASA. Acknowledgement: Judy Schmidt (geckzilla)"]https://cdn.spacetelescope.org/archives ... w1637a.jpg[/img3][hr][/hr]

A lone source shines out brightly from the dark expanse of deep space, glowing softly against a picturesque backdrop of distant stars and colourful galaxies.

Captured by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS), this scene shows PGC 83677, a lenticular galaxy — a galaxy type that sits between the more familiar elliptical and spiral varieties in the Hubble sequence.

This image was obtained as part of the Coma Cluster Survey. It reveals both the relatively calm outskirts and intriguing core of PGC 83677. Here, studies have uncovered signs of a monstrous black hole that is spewing out high-energy X-rays and ultraviolet light.

Deep-Sky-Astroteam wrote:Copyright Jens Zippel & Frank Iwaszkiewicz
SH2-114 The Flying Dragon Nebula

https://www.deep-sky-astroteam.de/sites ... k=o6LsTuhq
https://www.deep-sky-astroteam.de/de/sh2-114