Carbon Content in Dwarf Stars

Explore how white dwarfs contribute essential carbon to the cosmos, impacting debates about its origins in the Milky Way.

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Sagitarius A*: Van Gogh in the Milky Way

The colour scale in the image shows the amount of infrared (heat) radiation coming from warm dust particles in the filaments and luminous stars within a light year of the Galactic centre. The position of the black hole is indicated by an asterisk. The lines trace the magnetic field directions and reveal the complex interactions between the stars and the dusty filaments, and the impact that they and the gravitational force has on them. The observations were made with the largest telescope in Europe, which allowed details of the fine structure in the magnetic fields to be revealed for the first time.
- E. Lopez-Rodriguez / NASA Ames / University of Texas at San Antonio

A paper published on the Monthly Notices of the Royal Astronomical Society describes tha detailed mapping of the magnetic field around Sagittarius A*, or Sgr A*, the supermassive black hole at the center of the Milky Way. A researchers' team used the infrared camera CanariCam instaled on the Great Canary Telescope to obtain the data needed to reproduce the magnetic lines of gas and dusts that orbit around the center of the galaxy. The colors chosen by the researchers to visualize the structure of the magnetic lines give the result a style that recalls Vincent Van Gogh's paintings.

P F Roche, E Lopez-Rodriguez, CM Telesco, R Schödel, C Packham; The Magnetic Field in the central parsec of the Galaxy, Monthly Notices of the Royal Astronomical Society, sty129, 10.1093/mnras/sty129

Annihilator: Hollywood, the galaxy and everything

by @ulaulaman a review of #Annihilator, a #cosmic #comics by Grant Morrison and Frazer Irving

Rabbits are animals extremely prolific, almost legendary in their rate of reproduction, so that Leonardo Fibonacci, thanks to these cute rodents, discovered (or re-discovered) the series that bears his name: 1 1 2 3 5 8 13 21 and so on, and where each number is the sum of the previous two.
However, it is astonishing to note how pervasive within nature this series of numbers is: we can find it, for example, in the arrangement of seeds of sunflowers⁽¹⁾, in the structure of shells of turtles, in the spirals of seashells. Or, again, in the spiral galaxies⁽²⁾.

M51 (Whirlpool Galaxy) - source: reddit, NASA

Journey through the universe

The galactic matter, in fact, revolves around the center of every galaxy often making spiraling structures, arms of solid and gaseous matter that we can describe with the Fibonacci series as they fall toward the center, slowly swallowed up by an object apparently absurd but absolutely real: the supermassive black hole. So, within each spiral galaxy there is a black hole^{(3, 4)}, which at the same time is the reason for the existence⁽⁵⁾ and the ultimate fate of galaxies like our Milky Way, the center of which lies Sagittarius A*⁽⁶⁾.
Almost nothing escapes from the event horizon of this cosmic monster: let you imagine the matter while, piece by piece, falls within it, decomposed into its fundamental constituents, and the only trace of this meal is a simple, small radiation X⁽⁷⁾, a slight heat that escapes, evidence of a millennial digestion. It is in this border area that is brought Max Nomax, adventurer and genius, looking for "a cure for death", a way to be reunited with his beloved in life, the protagonist of a classic cosmic science fiction story written by the equally genial Ray Spass, Hollywood screenwriter in creative crisis and tormented by his manager, who presses him to get the script for a new film series, Annihilator.
With this latest work Grant Morrison, mixing the classic kirbyan superhero inspiration with real insights arrived from his Hollywood's patronage, builds a story that is a bit of an existential drama, a bit of a parody of the world of cinema, a bit of a great science fiction story. The comparison between creature and creator, here achieved simply with the description of their respective alternate adventures, brings near the two main characters, both anti-heroes, and from another point of view move them away for motivation and potential, creative or destructive according to their motivation.

The black hole in the center of the galaxy

posted by @ulaulaman about #astronomy #SagittariusA #BlackHole #MilkyWay

Sagittarius A* (pronounced "Sagittarius A-star", standard abbreviation Sgr A*) is a bright and very compact astronomical radio source at the center of the Milky Way Galaxy, near the border of the constellations Sagittarius and Scorpius. It is part of a larger astronomical feature known as Sagittarius A. Sagittarius A* is believed to be the location of a supermassive black hole,^{(1, 2)} like those that are now generally accepted to be at the centers of most spiral and elliptical galaxies. Observations of the star S2 in orbit around Sagittarius A* have been used to show the presence of, and produce data about, the Milky Way's central supermassive black hole, and have led to the conclusion that Sagittarius A* is the site of that black hole⁽³⁾.

In the image there is an x-ray photo of Sgr A* from the paper by Wang et al. published on Science⁽⁴⁾.

the x-ray emission from Sgr A* can be described as the superposition of a pointlike source from the black hole itself, and a much larger extended cloud of emission about 2″ across. Within this cloud, we can identify over a hundred individually resolved bright stars, and infer thousands more that are too dim to detect.⁽⁵⁾

They also infer that

the temperature and density profile of the gas cloud surrounding Sgr A*. They show that over 99% of the gas never reaches the central black hole, but rather is ejected from the system⁽⁵⁾

There are also some unresolved questions: for example if the observed accretion rate is dued exclusively by Sgr A* or if there is another source for the data; or his low luminosity, orders of magnitude below its theoretical potential⁽⁵⁾.

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Horizon in the Milky Way

On twitter Filippo Menconi shared an incredible flash applet realized with Stéphane Guisard's photos. The applet is intercative: for example you can change point of view simply moving the mouse up and down, rigth and left. After some experiment, I try to realize a little video using the applet. I produce two videos, without changing in point of view. In particular I propose you the video with Clouds over us⁽¹⁾ by Seeking for a name like soundtrack:

I hope that you can like this little experiment. In every case, if you are curious, in the following part of the post, you can read the procedure that I use:

Tempest: another great timelapse

Some days ago Nasa published the following incredible photo:

It is an infrared mosaic produced using Hubble's shots and represent the Universe observed by the space telescope. But also from Earth we can observe some spectacular images, like the stars in the sky or the Milky Way. Thursday we see a greattimelapse from Jared Brandon and today I propose you another great timelapse, realized by Randy Halverson (via Universe Today):

I think it could represent the perfect fusion between Earth and Sky, like in this shots from the slideshow of the video:

Thanks also to Annarita Ruberto, who shared the video in Italy.

Milky Way in timelapse

Writing a card about Milky Way for Italian Olympiad Astronomy syllabus, I search for some video in timelapse about our galaxy, and I find some interesting videos and a great artist, or photographer, as you like. The photographer was cited on Daily Mail and Photo Blog on msbc.com (and other sites in the web), and this is his great photo (source):

Tommy Eliassen (facebook, 1X) is the photographer, and he is very talented.
But this is simple the introduction to the timelapse video of today, Mt Ruapehu Timelapse by Jared Brandon:

The name of our galaxy comes from greek mythology. Indeed Zeus put on Hera's chest his son Heracles. And the hero started to suck the divine milk in order to became immortal. But Hera waked up (she was spleeping) and she pushed Heracles away. In that moment a splash of milk from the breasts of the goddess became the Milky Way:

The origin of the Milky Way by Jacopo Tintoretto