Video Transcript
What type of astronomical object is
shown in the picture below? (A) A nebula, (B) a supernova, or
(C) a galactic halo.
Let’s begin by briefly reviewing
some information about each of the possible answer choices.
Option (A), a nebula is a large
cloud of gas and dust in space. It’s a loose collection of floating
particles. And under the right conditions, a
nebula can contract due to gravity and eventually form a solar system.
Next, option (B) says a
supernova. A supernova occurs when a star
violently explodes, sending lots of its mass and energy into the surrounding
space. The actual explosion of a supernova
only lasts for a minute or so. But interestingly, a nebula can be
formed from the remnants of a supernova, which may go on to eventually become a
solar system.
Moving on, option (C), a galactic
halo is the region of space surrounding a galaxy. Now, looking back at the photo, we
don’t see a galaxy. A galaxy is a collection of
billions of stars and will typically have a more defined shape than what we see in
this photo. Thus, we can reason that the
picture doesn’t show a galactic halo. So let’s eliminate option (C).
This photo also does not show a
supernova. If it did, we would see a very
bright spot, the explosion, that would far outshine everything else in the
photo. Let’s eliminate (B) as well.
Rather, the picture shows a loosely
shaped cloud with a few brighter areas of likely star formation. This description fits that of a
nebula, and indeed a nebula is the correct answer. This is a photo of the Orion
Nebula, and it’s actually visible in the night sky from most places on Earth. To the naked eye, it looks like a
blurry star, and it makes up part of Orion’s sword in the Orion constellation. Scientists consider this nebula to
be an example of a stellar nursery, since hundreds of new stars are being formed out
of this cloud of gas and dust that measures over 20 light-years wide.
Thus, answer choice (A) is
correct. We know that the type of
astronomical object shown in the picture is a nebula.
