Found Images: 2021 September

[bystander]

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Have you seen a great image or video somewhere that you think would make a great APOD? Nominate it for APOD! Please post as much information here as you have about the image/video with a link to any source(s) for it you know of here, and the editors will take a look.

When posting the image itself, please do not post anything larger than a thumbnail here; please honor the copyright holder's copyright.

Please keep hotlinked images under 500K.

Thank you!

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[starsurfer]

PaRasMoMi 1
https://www.astrobin.com/wevsu6/
Data: Patrick Dufour
Processing: Utkarsh Mishra

You can read more about this discovery here.

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PaStDr 4
https://www.astrobin.com/vjd117/
Copyright: Marcel Drechsler/Xavier Strottner/Chilescope

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PN G136.7+61.9
https://telescopius.com/pictures/view/9 ... oris_us5wu
Copyright: Boris Chausov

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PN G026.9+04.4 and Sh2-62
http://www.atacama-photographic-observa ... php?id=175
Copyright: Thierry Demange, Richard Galli and Thomas Petit

[starsurfer]

NGC 4860
https://esahubble.org/images/potw1838a/
Copyright: ESA/Hubble & NASA

Click to view full size image

[Ann]

NGC 4860
https://esahubble.org/images/potw1838a/
Copyright: ESA/Hubble & NASA

Click to view full size image

That is, of course, a great image. As usual, I wonder about the colors.

ESA/Hubble wrote:

Colors & Filters

Optical
350 nm very broad

Optical
350 nm very broad

Optical
600 nm very broad

Optical
600 nm very broad

So we have two very broadband filters, one centered at 350 nm (near ultraviolet) and one at 600 nm (orange).

It seems clear to me that elliptical galaxies emit more orange than ultraviolet light, more yellow than green light, and more red than blue light. Yet the giant elliptical galaxy NGC 4869 is white to bluish white in color, whereas the prominent spiral galaxy, NGC 4858, displays reddish arms.

It gets even weirder when we look at a few of the background galaxies:

Two of the background galaxies, which I have marked with blue arrows, have prominent bulges and weak arms with no obvious star formation at all. We expect such galaxies to emit more orange than ultraviolet light.

The third galaxy displays a magnificent set of spiral arms, which undoubtedly contain blue star clusters, pink emission nebulas and dark dust lanes. We expect such spiral arms to emit more ultraviolet than orange light, and we expect such spiral galaxies to have bluish arms and yellow centers. But in infrared light, we expect them to have centers that are mapped to blue and arms that are mapped to red.

M74 is optical light. Photo: NGC 1535.

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M74 as observed with the Spitzer Space Telescope as part of the Spitzer Infrared Nearby Galaxy Survey. The blue colors represent the 3.6 micrometre emission from stars. The green and red colors represent the 5.8 and 8.0 micrometre emission from polycyclic aromatic hydrocarbons and possibly dust.

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The ESA/Hubble image looks like it is an optical image trying to imitate the color scheme of an infrared image.

Ann

[bystander]

Eclipsed Moon at Paranal
ESO Picture of the Week | 2021 Sep 06

Image Credit: Yuri Beletsky (LCO)/ESO

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Like Atlas holding up the sky in the Ancient Greek myth, it looks like ESO’s Very Large Telescope (VLT) is supporting the Moon in this extraordinary picture of a total lunar eclipse at the Paranal Observatory in Chile’s Atacama Desert. The photograph was taken on 26 May 2021 by astrophotographer Yuri Beletsky and it is featured in the ESO Calendar 2022.

To take this Picture of the Week, some detailed planning was required on the part of the photographer. Careful calculations allowed him to pinpoint a location nine kilometres to the east of Paranal, where the setting lunar eclipse would be briefly visible just above the domes of the telescopes, glowing faintly in the early morning twilight.

A total lunar eclipse occurs when the Sun, Earth and Moon align, with the Earth between the Sun and Moon. The Earth’s shadow blocks direct sunlight, so that the only light reflected from the Moon’s surface has been refracted by Earth’s atmosphere, giving the Moon a reddish colour. Since sunlight is filtered by Earth’s atmosphere, astronomers often use lunar eclipses to understand the signatures that life can imprint on the atmosphere, which is extremely useful in our quest for life on other planets. ...

[bystander]

A Glittering Globular Cluster
ESA Hubble Picture of the Week | 2021 Sep 06

Image Credit: ESA/Hubble and NASA, A. Sarajedini

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This star-studded image from the NASA/ESA Hubble Space Telescope depicts NGC 6717, which lies more than 20,000 light-years from Earth in the constellation Sagittarius. NGC 6717 is a globular cluster, a roughly spherical collection of stars tightly bound together by gravity. Globular clusters contain more stars in their centres than their outer fringes, as this image aptly demonstrates; the sparsely populated edges of NGC 6717 are in stark contrast to the sparkling collection of stars at its centre.

The centre of the image also contains some interlopers from closer to home. Bright foreground stars close to Earth are surrounded by criss-cross diffraction spikes formed by starlight interacting with the structures supporting Hubble’s secondary mirror.

The area of the night sky which contains the constellation Sagittarius also contains the centre of the Milky Way, which is filled with light-absorbing gas and dust. This absorption of light — which astronomers refer to as extinction — makes studying globular clusters near the Galactic centre a challenging endeavour. To determine the properties of NGC 6717, astronomers relied on a combination of Hubble’s Wide Field Camera 3 (WFC3) and the Advanced Camera for Surveys (ACS).

[starsurfer]

NGC 2020 region
https://www.hansonastronomy.com/ngc-2020
Data: Martin Pugh
Processing: Mark Hanson

[starsurfer]

NGC 1398
http://www.cielaustral.com/galerie/photo127.htm
Copyright: Ciel Austral

[barretosmed]

The Messier 71 (NGC 6838) cluster


It is a globular cluster located in the constellation Sagittarius located approximately 13 000 light years from Earth.
For a long time, the classification of M71 was a dense open cluster, but nowadays it's pretty inconclusive, with little study to help astronomers understand exactly what the M71 is. One of great importance was in 2008, when Brazilian astronomer Alan Alves-Brito and his colleagues published a study entitled “Abundance variations in globular cluster M71 (NGC 6838), where they measured the indices of cyanide, hydrocarbons, calcium, magnesium and aluminum in the spectra of 89 different stars, as well as their radial velocities, colors, luminosity, effective temperatures and gravities.
Hence why today. M71 is classified as a very loosely concentrated globular cluster, much like M68 in the constellation Hydra.

Best details:
https://www.astrobin.com/full/czc0dz/0/

EQUIPMENTS:
ZWO ASI 6200MC PRO COLED
Espirit 150mm
57 x 100sec

Date: 07/13/2021
Location: Jales-SP-Brazil
Copyright: Fernando Oliveira de Menezes
E-mail: Barretosmed@hotmail.com

Click to view full size image

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Sh2-308
https://www.flickr.com/photos/97807083@N00/49897052377/
Copyright: Terry Robison

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Sh2-27
https://www.astrobin.com/9pnt1k/
Copyright: Nikita Misiura

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Sh2-174
https://www.astrobin.com/iixsbm/
Copyright: Jordan Marlière

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Sh2-29
https://www.eso.org/public/news/eso1740/
Copyright: ESO

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Abell 16
https://pbase.com/skybox/image/171935233
Copyright: Kevin Quin

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IPHASX J022045.2+631135
https://www.imagingdeepspace.com/iphasx ... 31134.html
Copyright: Peter Goodhew

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Patchick 5
https://www.starscapeimaging.com/Patchi ... hick5.html
Copyright: Jon Talbot

[bystander]

North Meets South
ESO Picture of the Week | 2021 Sep 13

Credit: P. Horálek & J. C. Casado / ESO

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Looking at this photo might make you feel a little topsy-turvy! This Picture of the Week captures both the Northern and Southern Hemisphere at once — the whole night’s sky in one mind-bending image — something that would be impossible to see in real life.

To create this image, photographers Petr Horálek and Juan Carlos Casado took two pictures at observatories located at the same latitudes in the Northern and Southern Hemispheres. The top half is a photo taken at the Instituto de Astrofísica de Canarias’ Roque de los Muchachos Observatory in La Palma in the Canary Islands, 29 degrees north of the equator, whilst the bottom half was taken at ESO’s La Silla Observatory in Chile’s Atacama Desert, 29 degrees south of the equator. When digitally stitched together, they create a continuous sweeping view of the night’s sky.

One of the most noticeable features in this picture is the eerie white glow radiating out vertically from its centre. This is the zodiacal light, a phenomenon caused by dust that pervades our Solar System scattering sunlight, which is only visible in areas with extremely dark skies free from light pollution. Shining brightly in the beam of the Northern Hemisphere Zodiacal Light is the planet Venus.

The bottom image shows several of the telescopes at La Silla, including the ESO 1-metre Schmidt telescope in the foreground. The reflective mirror seen upside-down in the top image is part of the Cherenkov Telescope Array (CTA), a group of gamma-ray telescopes observing some of the most energetic phenomena in the universe. A second array will be installed in the southern hemisphere close to ESO’s Paranal Observatory, via an agreement between CTA Observatory and ESO.

[bystander]

A Closer Look at Hubble’s 31st Anniversary Snapshot
ESA Hubble Picture of the Week | 2021 Sep 13

Click to view full size image 1 or image 2

Credit: ESA/Hubble and NASA, A. Nota, C. Britt

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This Picture of the Week showcases new views of the dual nature of the star AG Carinae, which was the target of the NASA/ESA Hubble Space Telescope’s 31st anniversary image in April 2020. This new perspective was developed thanks to Hubble’s observations of the star in 2020 and 2014, along with others captured by the telescope’s WFPC2 instrument in 1994. ...

The first image showcases the details of the ionised hydrogen and ionised nitrogen emissions from the nebula (seen here in red). In the second image, the blue demonstrates the contrasting appearance of the distribution of the dust that shines of reflected stellar light. Astronomers believe that the dust bubbles and filaments formed within and were shaped by powerful stellar wind.

This giant star is waging a tug-of-war between gravity and radiation to avoid self-destruction. The star is surrounded by an expanding shell of gas and dust — a nebula — that is shaped by the powerful winds emanating from the star. The nebula is about five light-years wide, equal to the distance from here to our nearest star, Alpha Centauri.

AG Carinae is formally classified as a Luminous Blue Variable because it is hot (blue), very luminous, and variable. Such stars are quite rare because there are not many stars that are so massive. Luminous Blue Variable stars continuously lose mass in the final stages of their life, during which a significant amount of stellar material is ejected into the surrounding interstellar space, until enough mass has been lost that the star has reached a stable state. ...

viewtopic.php?t=41643

[the_astronomy_enthusiast]

This incredible shot was voted Astrobin's image of the day!
Copyright: Jeff Ridder (https://www.instagram.com/deepspacecrozet/)

[starsurfer]

Cave Nebula (Sh2-155)
https://www.astrobin.com/jovmgq/
Copyright: Jonathan Piques

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NGC 267 region
https://www.astrobin.com/i7auwk/
Copyright: Carlos Taylor

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IC 4633 region
https://www.flickr.com/photos/97807083@N00/51425326453/
Copyright: Terry Robison