by Ann » Sat Aug 17, 2019 12:39 pm
Great picture, Boomer!
For myself, I've literally spent hours trying to find a picture I remember, an old photographic plate of
the Orion constellation, where Betelgeuse is almost invisible. The reason for the strange appearance of Betelgeuse in old astronomical photographs is that these photographs were made using blue and ultraviolet-sensitive plates, and Betelgeuse emits so little blue light that it virtually disappeared in those photographs!
None of the pictures I found is not the one I was looking for, but they will have to do:
Orion photographed in 1890 by William Pickering.
Note that you can actually see Barnard's Loop,
but Betelgeuse is insignificant to say the least. The Horsehead Nebula.
Harvard College Observatory, 1888.
In the picture at left,
Orion's Belt with Almilam, Alnitak and Mintaka (above center) is so overexposed that it looks like one elongated blob. The
Orion Nebula (center) looks like another blob, and Rigel (center right) is so overexposed that it looks like yet another blob. Bellatrix (top right) and Saiph (center left) look bright. But Betelgeuse, top left, looks really faint, since the photo was made with a blue-sensitive photographic emulsion.
The other picture is the one in which the Horsehead Nebula was first discovered. Two Orion Belt's stars, Alnitak, center left, and Alnilam (top left), look very bright.
The Flame Nebula looks like some faint fluff to the lower left of Alnitak.
The Horsehead Nebula is just faintly visible as a dark shape to the right of Alnitak.
Astrophotography has come a long way, baby. But unsurprisingly enough, I like those old blue-sensitive pictures.
Ann
Great picture, Boomer! :D
For myself, I've literally spent hours trying to find a picture I remember, an old photographic plate of [url=https://i.pinimg.com/originals/35/d2/78/35d2783b4a163ffeee204801a4a89543.jpg]the Orion constellation[/url], where Betelgeuse is almost invisible. The reason for the strange appearance of Betelgeuse in old astronomical photographs is that these photographs were made using blue and ultraviolet-sensitive plates, and Betelgeuse emits so little blue light that it virtually disappeared in those photographs! :shock: None of the pictures I found is not the one I was looking for, but they will have to do:
[float=left][img2]https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcT-k632h2wRw_5ZFGu5gL1sFMn_ftcS-mw_nx6kQfosoIYCfcwq[/img2][c][size=85]Orion photographed in 1890 by William Pickering.
Note that you can actually see [url=https://upload.wikimedia.org/wikipedia/commons/3/35/BarnardLoopHunterWilson.jpg]Barnard's Loop[/url],
but Betelgeuse is insignificant to say the least.[/size][/c][/float] [float=right][img2]https://3.bp.blogspot.com/-50NLplCCUgc/VAip39S8RAI/AAAAAAAARt8/FoUGL_953N8/s1600/base.jpg[/img2][c][size=85]The Horsehead Nebula.
Harvard College Observatory, 1888.[/size][/c][/float]
In the picture at left, [url=https://i.pinimg.com/originals/f0/4e/73/f04e73f72bd4fb60cf89e94d37741764.jpg]Orion's Belt[/url] with Almilam, Alnitak and Mintaka (above center) is so overexposed that it looks like one elongated blob. The [url=https://astrobackyard.com/wp-content/uploads/2019/02/orion-nebula-HDR-photoshop.jpg]Orion Nebula[/url] (center) looks like another blob, and Rigel (center right) is so overexposed that it looks like yet another blob. Bellatrix (top right) and Saiph (center left) look bright. But Betelgeuse, top left, looks really faint, since the photo was made with a blue-sensitive photographic emulsion.
The other picture is the one in which the Horsehead Nebula was first discovered. Two Orion Belt's stars, Alnitak, center left, and Alnilam (top left), look very bright. [url=https://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Flame_Nebula_NGC_2024.jpg/591px-Flame_Nebula_NGC_2024.jpg]The Flame Nebula[/url] looks like some faint fluff to the lower left of Alnitak. [url=https://www.constellation-guide.com/wp-content/uploads/2014/01/Horsehead-Nebula-in-Orion-1024x678.jpg]The Horsehead Nebula[/url] is just faintly visible as a dark shape to the right of Alnitak.
Astrophotography has come a long way, baby. But unsurprisingly enough, I like those old blue-sensitive pictures. :wink:
Ann