Alan Friedman takes mind-blowing photos of the sun from home


13 Responses to “Alan Friedman takes mind-blowing photos of the sun from home”

  1. Richard Marinos says:

    Lesser moment of pedantry: The surface of the sun is ~5700K. 

  2. joe blough says:

    very interesting tedx talk. i guess the image is going to go viral again now that it’s on the boing.

    he says that it’s not possible to capture the faint stuff from the city, which is not strictly true. with the use of narrowband filters you can image all sorts of emission nebulae. it’s challenging but not impossible.

  3. Paul Renault says:

    Err, wouldn’t the section of the Sun facing us be brighter that the sections facing away from us – notably at and near the edge?

    • Antinous / Moderator says:

      Why? Luminous objects and reflective objects work differently.

      • Paul Renault says:

        They do, and they don’t. 

        If an object is reflecting like a mirror, then it depends on too many particulars…

        If an object is reflecting like the moon, then it depends (like the mirror ‘example’) of the position of the light source. 

        See here, where the Sun is behind the observer, giving a full Moon.  Pretty uniform illumination:

        And here, where the Sun is to the side of the observer, giving a half-moon.  Note that the surface illuminated at a shallow angle is darker.

        When you’re looking at the Moon, you’re looking at a sunlit object – much like looking at a sunlit object here on terra firma.  When you photograph the Moon, you must use an exposure time that’s the same as taking a picture of a friend who’s sunlit.  Really.

        For light sources which are diffuse, like the Sun, it’s kinda like the light given off by the full Moon, but for the Sun, it’s a little different.
        See here:

        The very thin rim/edge of the Sun is brighter, but that’s the corona.  And it’s a view through a thicker slice of the corona right near the surface – giving more photons coming .

        Note, the brightness of the Sun in this photograph seems uniform.  I’ll have to try some photographs of the Sun myself, then de-focus them slightly to confuse the surface features, to see if the brightness is uniform.

  4. CliffStoll says:

    I was delighted to meet Alan Friedman at several meetings of the Buffalo Astronomical Association – wonderful guy who brings astronomy to the neighborhood.  First time I met him was on the sidewalk, where he had set up a telescope for passerbys.  Beautiful views of the moon & Jupiter.

    Alan follows in the footsteps of several other solar astronomers and craftspeople in Buffalo: 

    Walter Semerau, who built (by hand!) a high resolution spectroheliograph.  It was squeezed next his washing machine — and the solar tower in his backyard was on stilts alongside the clothesline.

    Alan Gee, built (again, by hand!) an 8-angstrom prominence hydrogen filter – an optical filter created by grinding and polishing blocks of quartz (Before the advent of modern evaporated optical filters)

    Ernst Both, the curator of astronomy at the Buffalo Museum of Science, who created a solar observatory (with spectrograph and monochrometer) located in Buffalo’s inner-city. 

    I’m honored and humbled to have met each of these men; I studied under Ernst Both for many years. 

    Later, when working at Kitt Peak National Observatory, I was struck by how much these people had accomplished in building instruments and bringing the excitement of astronomy to the community. 

  5. Steve White says:

    Anybody else see the gorilla?

  6. anechoic says:

    that photo really looked like a human female egg at first glance! 

    as above so below!

  7. pjcamp says:

    The Sun doesn’t actually have a surface. It’s just a big cloud of gas that gets progressively less dense the further out you go. As it happens, the mean free path of photons drops off a cliff at a critical density so what looks like the surface is just the point where photons ceased experiencing significant scattering.

    This moment in pedantry brought to you by I’m trying to avoid finishing writing that paper.

  8. artao says:

    you know, there’s literally THOUSANDS of people who take stunning photos of the sun, in numerous wavelenghts. Why exactly is there this article focusing on this guy as if he’s some super-stupendous photographer? sure, they’re nice photos. but you make it out to sound like he developed this whole technique, which he certainly did not.

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