What a stunningly beautiful image. Do follow the link,
The camera's exposure, to see the incredibly star-studded sky of the full resolution image.
APOD Robot wrote:
The camera's exposure reveals the stellar nursery's faint pinkish glow. Betelgeuse, giant star at Orion's shoulder, has the color of warm and cozy terrestrial lighting, but so does another familiar stellar giant, Aldebaran.
Indeed, the Orion Nebula is
pinkish, although that is a color that we have no hope of seeing with our eyes in any cosmic nebula. And Betelgeuse and Aldebaran both stand out because of their
yellow-orange color.
Orion constellation with long curving Barnard's Loop at left,
and round Lambda Orionis Nebula at top. Photo: Angel G. Fuentes.
But there are two more colors that should be pointed out in the image.
Two faint
red emission nebulas are visible in the APOD as well as in the image I have posted here at top. It's the long curving Barnard's Loop encircling much of the lower part of the Orion constellation, and the round Lambda Orionis Nebula at top.
The Lambda Orionis Nebula is ionized by hot, O8-type star Lambda Orionis, and Barnard's Loop may either be a supernova remnant, or else it might be ionized by the collective ultraviolet radiation of the hot stars in and near the Orion Nebula and Orion's Belt. It is interesting to see how much brighter, but also how much smaller, the Orion Nebula is compared with Barnard's Loop and the Lambda Orionis Nebula.
The second image I have posted, the one of the central Milky Way, brings out the rarity of blue stars in our galaxy.
A few prominent blue stars are visible in it, particularly Lambda, Nu and Kappa Scorpii (at lower left), and
the pink Lagoon Nebula, itself ionized by hot blue stars, stands out at upper right.
The two red (and dust-reddened) nebulas near Kappa and Nu Scorpii are the Cat's Foot Nebula and the Lobster Nebula.
But what dominates the scene is
a diffuse yellowish glow, emitted by hundreds of millions of mostly faint yellow and red stars.
Most stars in the Milky Way are faint and yellowish. We can see with our eyes that bright yellow-orange stars like Betelgeuse and Aldebaran are unusual.
But stars like Alnitak, Alnilam and Mintaka are unusual too, and not only for the beautiful line they create in the sky as they make up Orion's Belt (at least from our point of view), and for their very high luminosities. They are unusual for their bluish color too, and for their hot temperatures that create their color.
Hot bright blue stars are rare! Give them their due!
Ann
Northern Winter Night
