Starship Asterisk*

Image Credit: ESO/Petr Horálek

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The Search for habitable Planets EClipsing ULtra-cOOl Stars (SPECULOOS) telescopes sited at ESO’s Paranal Observatory in Chile’s Atacama Desert are usually the ones looking for new worlds, but this picture actually captures the observing site looking like a planet itself. This is constructed using a photography technique called stereographic projection, whereby a spherical image — like a 360º panorama — is projected onto a plane.

The mission of SPECULOOS is to detect terrestrial planets as they pass between us and their parent small, cool star in the solar neighbourhood, leading to a tiny, regular dimming in the star’s brightness. Exoplanets discovered by this so-called transit method can be studied in great detail, including making precise measurements of their mass and radius, and analysing their possible atmospheres and potential for life.

SPECULOOS, whose name is inspired by the sweet treat famous in Belgium, The Netherlands and Germany, comprises four telescopes, each with a one-metre primary mirror and cameras that are highly sensitive in the near-infrared.

In the background of “Planet SPECULOOS”, the lasers of ESO’s Very Large Telescope are being used to create artificial stars high up in the atmosphere to measure and correct turbulence. If you look carefully you can actually see these stars as a yellow dot where the laser beams end!

Image Credit: ESA/Hubble & NASA, D. Milisavljevic

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This NASA/ESA Hubble Space Telescope Picture of the Week features the galaxy NGC 6984, an elegant spiral galaxy in the constellation Indus roughly 200 million light-years away from Earth. The galaxy is a familiar sight for Hubble, having already been captured in 2013. The sweeping spiral arms are threaded through with a delicate tracery of dark lanes of gas and dust, and studded with bright stars and luminous star-forming regions.

These new observations were made following an extremely rare astronomical event — a double supernova in NGC 6984. Supernovae are unimaginably violent explosions on a truly vast scale, precipitated by the deaths of massive stars. These events are powerful but rare and fleeting — a single supernova can outshine its host galaxy for a brief time. The discovery of two supernovae at virtually the same time and location (in astronomical terms) prompted speculation from astronomers that the two supernovae may somehow be physically linked. Using optical and ultraviolet observations from Hubble’s Wide Field Camera 3 (WFC3), astronomers sought to get a better look at the site of the two supernovae, hopefully allowing them to discover if the two supernova explosions were indeed linked. Their findings could give astronomers important clues into the lives of binary stars.

As well as helping to unravel an astronomical mystery, these new observations added more data to the 2013 observations, and allowed this striking new image to be created. The observations — each of which covers only a narrow range of wavelengths — add new details and a greater range of colours to the image.

starsurfer wrote: ↑Mon Nov 01, 2021 11:38 pm PaStDr 8 and G354-33
https://www.astrobin.com/eqf4ng/
Copyright: Dana Patchick/Xavier Strottner/Marcel Drechsler/Chilescope

Click to view full size image

starsurfer wrote: ↑Mon Nov 01, 2021 11:23 pm HDW 2
https://www.hansonastronomy.com/sh2200
Copyright: Mark Hanson

Click to view full size image

Ann wrote: ↑Tue Nov 02, 2021 5:37 am

starsurfer wrote: ↑Mon Nov 01, 2021 11:38 pm PaStDr 8 and G354-33
https://www.astrobin.com/eqf4ng/
Copyright: Dana Patchick/Xavier Strottner/Marcel Drechsler/Chilescope

Click to view full size image

That's a superb image and an even better technical card, if you follow the link.

But there is one thing I'm wondering about. The temperature of the white dwarf is said to be 8868,67 K. Does that mean that the white dwarf is some 88 thousand degrees Kelvin?

Ann

Ann wrote: ↑Tue Nov 02, 2021 5:41 am

starsurfer wrote: ↑Mon Nov 01, 2021 11:23 pm HDW 2
https://www.hansonastronomy.com/sh2200
Copyright: Mark Hanson

Click to view full size image

That is an extremely beautiful image. Tell me, is the white dwarf visible here? Is it a tiny bluish object between two orange stars?

Ann

Image Credit: ESO/Enrichetta Iodice et al.

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The image shows a pair of overlapping spiral galaxies, NGC 3314a and b, in the top left, caught in a majestic cosmic dance — captured by ESO’s VLT Survey Telescope (VST).

But don’t let the perspective fool you! They are, in fact, not interacting at all. The two galaxies, located between 117 and 140 million light-years away in the constellation of Hydra, are actually physically unrelated and only appear to overlap when viewed from Earth. This unique alignment gives astronomers the opportunity to measure many properties of the galaxies, such as how dust absorbs starlight, and hence gain insight into their composition and evolution.

There is another hidden secret in this picture if you look closely at the lower right region: beyond this stunning cosmic dance you will find a faint yellowish smudge, the signature of an ultra-diffuse galaxy (UDG). UDGs are objects as large as the Milky Way but with 100 – 1000 times fewer stars. These galaxies are extremely faint and lack star-forming gas, which makes them appear almost like a smudge in the night sky. This UDG, named UDG 32, is one of the faintest and most spread out galaxies in the Hydra I cluster.

This image was taken as part of a much larger project, the VST Early-type Galaxy Survey (VEGAS), whose goal is to investigate very faint structures in galaxy clusters — large groups of galaxies held together by gravity. The study, led by Enrichetta Iodice from the Istituto Nazionale di Astrofisica in Italy, suggests that UDG 32 may have formed out of the filaments stemming from NGC 3314a, but more observations are needed to confirm this.

Image Credit: ESA/Hubble & NASA, A. Riess et al.

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This image from the NASA/ESA Hubble Space Telescope features the spiral galaxy Mrk 1337, which is roughly 120 million light-years away from Earth in the constellation Virgo. Hubble’s Wide Field Camera 3 (WFC3) snapped Mrk 1337 at a wide range of ultraviolet, visible and infrared wavelengths, producing this richly detailed image. Mrk 1337 is a weakly barred spiral galaxy, which as the name suggests means that the spiral arms radiate from a central bar of gas and stars. Bars occur in roughly half of spiral galaxies, including our own galaxy the Milky Way.

These observations are part of a campaign to improve our knowledge of how fast the universe is expanding. They were proposed by Adam Riess, who was awarded a Nobel Laureate in physics 2011 for his contributions to the discovery of the accelerating expansion of the Universe, alongside Saul Perlmutter and Brian Schmidt.

Image Credit: ESO/Petr Horálek

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Yes, the bright light you see in the centre of this picture, shining below the Milky Way’s dark, pinkish belt, is in fact the king of the planets in the Solar System! Jupiter is flanked by two hills hosting ESO’s Very Large Telescope (VLT) (left) and VISTA (right) in the Atacama Desert in Chile.

Jupiter is the largest planet in our Solar System and the third brightest object in the night sky, only outshone by the Moon and Venus. Naming it after the god of the sky and thunder is certainly fitting! Mainly made of hydrogen and helium, one of Jupiter’s most distinctive marks is the famous great red spot on its surface, the largest storm in the Solar System.

Jupiter has been observed by the 8.2-m telescopes of the VLT on more than one occasion. The VISIR instrument captured a stunning high resolution infrared image of Jupiter, key to understanding how energy and matter flow through its atmosphere. The CRIRES infrared spectrograph –– an instrument that breaks light into its constituent colours –– mapped an area in Jupiter’s upper atmosphere that is 200 ºC colder than its surroundings. Using MAD, a prototype instrument to correct atmospheric turbulence, the VLT obtained incredibly sharp images of the planet. Jupiter was also among the first test targets of MUSE, an instrument that can image astronomical objects at thousands of different colours simultaneously. Jupiter is the king, and all eyes are on him!

Image Credit: ESA/Hubble & NASA, A. Seth

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This astronomical portrait from the NASA/ESA Hubble Space Telescope showcases an edge-on view of the majestic spiral galaxy UGC 11537. Hubble’s Wide Field Camera 3 has captured the tightly wound spiral arms swirling around the heart of UGC 11537 at infrared and visible wavelengths, showing both the bright bands of stars and the dark clouds of dust threading throughout the galaxy.

UGC 11537 is 230 million light-years away in the constellation Aquila, and lies close to the plane of the Milky Way. Being so close to the starry band of the Milky Way means that foreground stars from our own galaxy have crept into the image — the two prominent stars in front of UGC 11537 are interlopers from within the Milky Way. These bright foreground stars are surrounded by diffraction spikes — imaging artifacts caused by starlight interacting with Hubble’s inner structure.

This image came from a set of observations designed to help astronomers weigh supermassive black holes in distant galaxies. The combination of Hubble’s sharp-eyed observations and data from ground-based telescopes allowed astronomers to make detailed models of the mass of stars in these galaxies, which in turn helps constrain the mass of supermassive black holes.