Starship Asterisk*

Credit: ESA/Hubble & NASA, Vera Rubin et al

---

This Hubble Picture of the Week shows the spiral galaxy Messier 98, which is located about 45 million light-years away in the constellation of Coma Berenices (Berenice's Hair). It was discovered in 1781 by the French astronomer Pierre Méchain, a colleague of Charles Messier, and is one of the faintest objects in Messier’s astronomical catalogue.

Messier 98 is estimated to contain about a trillion of stars, and is full of cosmic dust — visible here as a web of red-brown stretching across the frame — and hydrogen gas. This abundance of star-forming material means that Messier 98 is producing stellar newborns at a high rate; the galaxy shows the characteristic signs of stars springing to life throughout its bright centre and whirling arms.

This image of Messier 98 was taken in 1995 with the Wide Field and Planetary Camera 2 (WFPC2), an instrument that was installed on the NASA/ESA Hubble Space Telescope from 1993 till 2009. These observations were taken in infrared and visible light as part of a study of galaxy cores within the Virgo Cluster, and feature a portion of the galaxy near the centre.

Image Credit: ESO/Petr Horálek

---

ESO’s observatories located on the mountains of Chile — La Silla, Paranal and Chajnantor Plateau — are home to a wide range of telescopes built and operated by the organisation’s 16 Member States. As time passes, older telescopes are slowly overtaken by their newer and more advanced peers. One of these old-timers is pictured here: the Swedish-ESO Submillimetre Telescope (SEST).

Built back in 1987 at La Silla, the SEST was a groundbreaking instrument. It was the only large telescope in the southern hemisphere to study radio waves from objects in the distant Universe (known as submillimetre astronomy). A huge dish, with a diameter of 15 metres, the telescope was able to observe some of the most extreme phenomena in the cosmos.

Eventually, however, newer and more advanced telescopes — such as the Atacama Large Millimeter/submillimeter Array (ALMA) and Atacama Pathfinder Experiment (APEX), both situated on Chajnantor Plateau — began to produce better measurements and observations, and the SEST was decommissioned in 2003.

However, the story is not quite over. SEST may no longer observe, but the telescope’s reflective dish still stands proudly at La Silla, acting as a mirror for the site’s beautiful nighttime skies.

bystander wrote: ↑Mon Jun 17, 2019 2:24 pm Spiral, Elliptical, Irregular
ESA Hubble Picture of the Week | 2019 Jun 17

Image Credit: NASA, ESA and F. Bauer

---

This image shows an irregular galaxy named IC 10, a member of the Local Group — a collectiongrouping of over 50 galaxies inwithin our cosmic neighbourhood that includes the Milky Way.

IC 10 is a remarkable object. It is the closest-known starburst galaxy to us, meaning that it is undergoing a furious bout of star formation fueled by ample supplies of cool hydrogen gas. This gas condenses into vast molecular clouds, which then form into dense knots where pressures and temperatures reach a point sufficient to ignite nuclear fusion, thus giving rise to new generations of stars.

As an irregular galaxy, IC 10 lacks the majestic shape of spiral galaxies such as the Milky Way, or the rounded, ethereal appearance of elliptical galaxies. It is a faint object, despite its relative proximity to us — just of 2.2 million light-years. In fact, IC 10 only became known to humankind in 1887, when American astronomer Lewis Swift spotted it during an observing campaign. The small galaxy remains difficult to study even today, because it is located along a line-of-sight which is chock-full of cosmic dust and stars.

A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Nikolaus Sulzenauer, and went on to win tenth prize.

Ann wrote: ↑Mon Jun 17, 2019 3:05 pm

Click to view full size image

IC 10. Image Credit: NASA, ESA and F. Bauer

Click to view full size image

IC 10. Photo: Lowell Observatory.

I don't know about you, but I found it hard to spot the galaxy for all the details in it in the NASA/ESA/Hubble image. In particular, I didn't find the nebulas very prominent at all. So I prefer the picture at right, which combines optical wavelengths (possibly RGB) with H-alpha emission. Here the nebulas stand out in a satisfying way, as befits a starburst galaxy.

Ann

Image Credit: NASA, ESA and F. Bauer

---

This image shows an irregular galaxy named IC 10, a member of the Local Group — a collectiongrouping of over 50 galaxies inwithin our cosmic neighbourhood that includes the Milky Way.

IC 10 is a remarkable object. It is the closest-known starburst galaxy to us, meaning that it is undergoing a furious bout of star formation fueled by ample supplies of cool hydrogen gas. This gas condenses into vast molecular clouds, which then form into dense knots where pressures and temperatures reach a point sufficient to ignite nuclear fusion, thus giving rise to new generations of stars.

As an irregular galaxy, IC 10 lacks the majestic shape of spiral galaxies such as the Milky Way, or the rounded, ethereal appearance of elliptical galaxies. It is a faint object, despite its relative proximity to us — just of 2.2 million light-years. In fact, IC 10 only became known to humankind in 1887, when American astronomer Lewis Swift spotted it during an observing campaign. The small galaxy remains difficult to study even today, because it is located along a line-of-sight which is chock-full of cosmic dust and stars.

A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Nikolaus Sulzenauer, and went on to win tenth prize.

Image Credit: Petr Horálek/ESO

---

This stunning photograph shows some of the antennas comprising the Atacama Large Millimeter/submillimeter Array (ALMA), all observing a panoramic view of the Milky Way’s centre. There is far more to ALMA than shown here; the array can span distances of up to 16 kilometres and is formed of 66 individual antennas!

Some features visible in the sky include Crux (The Southern Cross) just above and to the right of the nearest antenna, and the Carina Nebula slightly further to the right.

Astronomers use ALMA to peer into gigantic star-forming molecular clouds, and to observe galaxies forming at the very edge of the observable Universe. The green lights visible on the telescopes are a normal part of their operation, but in this scene they also cast an ethereal, otherworldly glow over the Chilean site.

This photograph was taken by Petr Horálek, one of our ESO Photo Ambassadors.

Ann wrote: ↑Sat Jun 15, 2019 8:10 pm

starsurfer wrote: ↑Sat Jun 15, 2019 7:23 pm NGC 7793
https://www.eso.org/public/images/eso0914b/
Copyright: ESO

Click to view full size image

Click to view full size image

M33. Image Credit & Copyright: Robert Gendler, Subaru Telescope (NAOJ)
Image data: Subaru Telescope, Robert Gendler, Brigham Young University Obs.,
Johannes Schedler

When I first saw that picture of NGC 7793, my first thought was, Oh, that's another picture of M33.

Sure there are differences, but sure there are similarities too, aren't there?

Ann