Helix Nebula
FYNebulas
FYNebulas
Helix Nebula
Helix Nebula
Helix Nebula
Infrared Helix nebula
This spectacular object, a dying star unraveling into space, is a favorite of amateur and professional astronomers alike. NASA’s Spitzer Space Telescope has mapped the expansive outer structure of the six-light-year-wide nebula, and probed the inner region around the central dead star to reveal what appears to be a planetary system that survived the star’s chaotic death throes.
• Source: NASA/JPL
ω Centauri’s red giants confirm stellar evolution models
A new study, led by Mariela Vieytes from the University of Buenos Aires, demonstrates one of the necessary conditions for predictions of stellar post-main sequence evolution.
Astronomers need to establish that stars undergo significant amounts of mass loss (~0.1-0.3 M☉) during their red giant branch evolution. They expected to find confirmation of this by detecting gas congregating in the cores of globular clusters after being shed by stars evolving along the RGB. Yet searches for this gas came up mostly empty.
Eventually astronomers realized that gas would be stripped relatively quickly as globular clusters plunged through the galactic plane. But this left them with the need to confirm the prediction in some other manner.
One way to do this is to look at the stars themselves. If they show velocities in their photospheres greater than the escape velocity, they will lose mass. Just how much higher will determine the amount of mass lost.
By analyzing the Doppler shift of specific absorption lines of several stars in the cluster ω Centauri, the team was able to match the amount of mass being lost to predictions from evolutionary models. From this, the team concluded that their target stars were losing between the rates of mass loss are estimated as a few 10-9 and 10-10 M☉ yr-1. This is in general agreement with the predictions set forth by evolutionary models.
Image: As they get older, Sun-like stars become red giants and shed mass.
• Source: Universe Today • The paper is available at http://arxiv.org/1011.1260v1.pdf
Helix Nebula
(Source: invaderxan)
(via brosephstalin)
Wow. This really puts things into perspective.
Really cool.
I love the presentation of all this. it’s just so much to take in all in one sitting. it completely blows my mind, even though it includes a bunch of stuff I already knew but this like… expands it, and shows it. So well. Wow.
(via nancybotwin)
