Black Holes – In a Nutshell

Dec 20, 2015

YouTube account “In a Nutshell – Kurzgesagt” has made this fantastic video on Black Holes with some amazing animations. It does not stop with the video however – check out this great collection of the best resources and content from all over the web on the cosmic quandaries on Wakelet: https://wakelet.com/wake/46MKeCLTKk

Here is the Black Hole Wake we mentioned above, embedded:

3 comments on “Black Holes – In a Nutshell

  • Meanwhile around our own galaxy’s central black hole:-

    http://www.bbc.co.uk/news/science-environment-35267571

    Astronomers have measured the age of 70,000 stars across the Milky Way and put the results into a galactic map.

    It confirms what was already suspected about our galaxy’s growth: it started in the middle and grew outward.

    This can be seen in the abundance of old stars near the centre of the disc.

    Presented at the 227th meeting of the American Astronomical Society in Florida, it is the largest such map ever assembled.

    “We’re characterising in really unprecedented detail how the galaxy is formed, via this snapshot of stellar ages across the disc,” lead researcher Melissa Ness told the BBC.

    The tendrils of the map extend out from the Earth, beyond the centre of the galaxy in one direction, and out to the very far reaches of the disc in the other.

    “And we not only have these ages in the plane of the disc, but also moving up above the galactic plane,” added Dr Ness, who works at the Max Planck Institute for Astronomy in Germany.

    To calculate the age of each star, she and her colleagues used data from two telescopes.

    Firstly, the Apogee project – part of the ground-based Sloan Digital Sky Survey – sampled many thousands of stars, 300 at a time, using a wide swathe of wavelengths. These spectra help astronomers to work out the chemical composition of stars, but cannot determine their age directly.

    So the team started with a subset of stars that had also been observed from space by the Kepler satellite. This telescope stares at a few stars for a long period of time, and can establish their mass.

    “If we know the mass of these Kepler stars, we can determine their ages,” Dr Ness explained. This enabled her team to build a model relating a star’s mass and age to its colour spectrum, from the Apogee data.

    That model could then be deployed to calculate ages for all the remaining stars, based purely on their spectra.

    Progress mapping the evolutionary history of the Milky Way galaxy!



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