by Ann » Tue Jan 11, 2022 6:38 am
Congrats, Matt Harbison! It is interesting to see how your image makes the red Sigma Orionis nebula bigger than what is traditionally seen, and there is a blue reflection nebula between Mintaka and Alnilam.
For myself, I love stars, particularly (of course) blue stars. So let's compare today's APOD with an image with stars:
Note in both images the large and strikingly red nebula surrounding
Sigma Orionis. Sigma Orionis is a multiple star and the central star of an entire very young cluster containing several pre-main sequence stars. The hottest, brightest component of Sigma Orionis is a star of spectral class O9.5 V, with a temperature of 35,000 K and a luminosity over 40,000 L
☉. Its close binary companion belongs to spectral class B0V, with a temperature of 31,000 K and a luminosity of 18,600 L
☉. Together, these two stars emit furious ultraviolet light that makes hydrogen glow red around them, and they provide the red background against which the Horsehead Nebula can be seen.
Ann
Congrats, Matt Harbison! It is interesting to see how your image makes the red Sigma Orionis nebula bigger than what is traditionally seen, and there is a blue reflection nebula between Mintaka and Alnilam.
For myself, I love stars, particularly (of course) blue stars. So let's compare today's APOD with an image with stars:
[float=left][img3="Orion's Belt Region in Gas and Dust. Image Credit & Copyright: Matt Harbison (Space4Everybody), Marathon Remote Imaging Observatory"]https://apod.nasa.gov/apod/image/2201/OrionStarFree3_Harbison_1080_annotated.jpg[/img3][/float][float=right][attachment=0]Orions Belt Horsehead Sigma Orionis Orion Nebula Terry Hancock annotated.png[/attachment][c][size=85][color=#0040FF]Image: Terry Hancock[/color][/size][/c][/float]
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Note in both images the large and strikingly red nebula surrounding [url=https://en.wikipedia.org/wiki/Sigma_Orionis]Sigma Orionis[/url]. Sigma Orionis is a multiple star and the central star of an entire very young cluster containing several pre-main sequence stars. The hottest, brightest component of Sigma Orionis is a star of spectral class O9.5 V, with a temperature of 35,000 K and a luminosity over 40,000 L[sub]☉[/sub]. Its close binary companion belongs to spectral class B0V, with a temperature of 31,000 K and a luminosity of 18,600 L[sub]☉[/sub]. Together, these two stars emit furious ultraviolet light that makes hydrogen glow red around them, and they provide the red background against which the Horsehead Nebula can be seen.
[float=left][img3="Sigma Orionis, the Horsehaed Nebula and various stars belonging to the Sigma Orionis cluster. Image: Lithopsian."]https://upload.wikimedia.org/wikipedia/commons/thumb/4/48/Sigma_orionis_cluster.jpg/1280px-Sigma_orionis_cluster.jpg[/img3][/float]
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Ann