Starship Asterisk*

Fred the Cat wrote:

geckzilla wrote:

starsurfer wrote:Asteroid 3200 Phaethon
https://www.flickr.com/photos/dcrowson/24172223817
Copyright: Dan Crowson

Hubble was just looking at this rock yesterday.

They timed that just about right. When or how would one find the image?

[img3="Image Credit: NASA, ESA, STScI
Acknowledgment: S. Djorgovski (Caltech) and F. Ferraro (Bologna)"]https://cdn.spacetelescope.org/archives ... w1751a.jpg[/img3][hr][/hr]

It’s beginning to look a lot like Christmas in this NASA/ESA Hubble Space Telescope image of a blizzard of stars, which resembles a swirling storm in a snow globe.

These stars make up the globular cluster Messier 79, located about 40 000 light-years from Earth in the constellation of Lepus (The Hare). Globular clusters are gravitationally bound groupings of up to one million stars. These giant “star globes” contain some of the oldest stars in our galaxy. Messier 79 is no exception; it contains about 150 000 stars, packed into an area measuring just roughly 120 light-years across.

This 11.7-billion-year-old star cluster was first discovered by French astronomer Pierre Méchain in 1780. Méchain reported the finding to his colleague Charles Messier, who included it in his catalogue of non-cometary objects: The Messier Catalogue. About four years later, using a larger telescope than Messier’s, William Herschel was able to resolve the stars in Messier 79 and described it as a “globular star cluster.”

In this sparkling Hubble image, Sun-like stars appear yellow-white and the reddish stars are bright giants that are in the final stages of their lives. Most of the blue stars sprinkled throughout the cluster are aging “helium-burning” stars, which have exhausted their hydrogen fuel and are now fusing helium in their cores.

[c][imghover=https://cdn.spacetelescope.org/archives ... w1752b.jpg]https://cdn.spacetelescope.org/archives ... w1752a.jpg[/imghover]Credit: ESO, ESA/Hubble & NASA[/c][hr][/hr]

This image shows something spectacular: a galaxy cluster so massive that it is warping the space around it! The cluster, whose heart is at the centre of the frame, is named RCS2 J2327, and is one of the most massive clusters known as its distance or beyond.

Massive objects such as RCS2 J2327 have such a strong influence on their surroundings that they actually warp the space around them — this effect is known as gravitational lensing, and can cause light from more distant objects to be bent, distorted, and amplified, allowing us to see galaxies that would otherwise be far too distant for us to detect. Gravitational lensing is one of the predictions of Albert Einstein's General Theory of Relativity and can be observed in three different regimes: strong lensing, weak lensing, and microlensing. Unlike strong lensing, which produces stunning images of distorted galaxies, sweeping arcs, and phenomena known as Einstein rings, weak gravitational lensing is mostly studied statistically — but offers a way to measure the masses of cosmic objects, as shown here.

This image is a composite of observations from the HAWK-I instrument on ESO’s Very Large Telescope and the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys, and demonstrates an impressively detailed collaborative approach to studying weak lensing in the cosmos. The study found RCS2 J2327 to contain the mass of two quadrillion Suns!

The diffuse blue and white image is a mass map, showing the amount of mass thought to be contained within each part of the cluster. The creation of the map was only possible due to the exact measurements on the amount of gravitational lensing in the different areas of the cluster.

starsurfer wrote:Omega Centauri
https://www.astrobin.com/286586/0/
Copyright: Tommy Nawratil
b23aafbff16e02d610fba8990515f170.1824x0.jpg
Also includes Centaurus A and NGC 4945!