Suppose an advanced alien race discovered our little planet. From their great telescopes they could tell our atmosphere is rich in oxygen and water vapor, which would indicate this was a planet inhabited by living organisms. They therefore decide to send a probe to study our curious blue world. With their advanced technology, this alien species can send a probe across the vast distance of space using a device they call the Maguffin drive. The Maguffin drive can transport the probe to Earth almost instantly, but because of the tremendous energy it requires the probe can only stay on Earth for one second.
Four of a Kind
One of the most popular constellations is Orion the hunter. In the sword of Orion, just below the belt is a nebula known as the Orion Nebula. This nebula is a stellar nursery about 1300 light years away. At the heart of the Orion Nebula is a small cluster of very bright stars known as the Trapezium Cluster. Because Trapezium is bright and reasonably close to us, we’re able to make very precise measurements of the stars’ speed and motion. What we find is a bit of a puzzle.
Second Look
One of the advantages of modern astronomy is that most observational data gets stored in a raw form. This is particularly true for the major space telescopes. Most of that raw data is also stored publicly, either a certain time period or even as the data is gathered. This means that long after an observation is made, people can go through the data to analyze it in new ways. As a case in point, a team recently gathered old data from the Hubble Space Telescope, and processed it using new methods.
Brown Dwarf Desert
A brown dwarf is larger than a planet, but not large enough to be considered a star. Stars undergo fusion in their cores, but a brown dwarf lacks the mass necessary to initiate fusion. At the same time, they are more like stars than planets, and can have at atmospheric temperature of 2000 K. So these objects occupy a middle ground between star and planet.
Wondrous Star
Mira is a red star in the constellation Cetus. It is a variable star, meaning that its brightness changes over time. The name Mira is Latin for “wondrous”, and so Mira is indeed a wondrous star.
Star Dates
Determining the age of a star poses a bit of a challenge for astronomers. After all, stars exist over a timescale of billions of years, and they are light years away. We can’t use radiometric dating like we do for rocks and other objects on Earth. So just how do we determine the age of a star? It turns out that there are several ways, and it’s getting easier to do.
Cycle of Stars
The Sun’s magnetic field varies over time, which means the activity of the Sun varies. The earliest observation of this cycle was seen in sunspots. We can observe similar activity in other stars by observing what are known as their H-K cycles.
Siblings
Stars don’t form alone. They form as part of a stellar nursery. We know this because we can see new stars forming in this way, such as in the Orion nebula. This means, of course, that our own Sun also formed in a stellar nursery with lots of other stars. There are stars out in the galaxy that are siblings to our Sun, and we think we know where a few of them are.
Eagle Eye
While many stars rotate at a slow pace, some stars rotate very rapidly. One of these is the star Altair, the brightest star in the constellation Aquilla.