Space and astronomy news
Just a few years ago, Pluto was considered unusual for Kuiper Belt Objects because it has a moon. Now three of the four largest KBOs have been discovered with moons, and it’s causing astronomers to reconsider how this came about. Only 11% of smaller KBOs have a moon, and probably captured them with gravity. But the moons for the larger objects likely formed when similarly-sized planetoids collided together, and the debris turned into their moons.
Arizona astronomers have found a collection of stars that really shouldn’t exist. They’re located in the debris of NGC 2782, which is the result of a merger between a Milky Way-sized galaxy and a smaller galaxy. These kinds of mergers are very common in the Universe; however, they usually leave behind debris that doesn’t contain the right ingredients to form stars – neutral hydrogen gas and molecular gas. But NGC 2782 has regions with stars that formed after the collision.
Greetings, fellow SkyWatchers! The busiest place to be as the week begins is the “Beehive” and the peak of the Delta Cancrid meteor shower, but if you’re clouded out, dont worry – the Coma Berenicids will be along mid week. Come along as we explore Messier objects and one of the finest carbon stars around – R Leporis. So grab those binoculars or telescopes and head out into the night because…
Here’s what’s up!
Astronomers think they might have found a “dark galaxy”, that has no stars and emits no light. Although the galaxy itself, located 50 million light years from Earth, is practically invisible, it contains a small amount of neutral hydrogen which emits radio waves. If astronomers are correct, this galaxy contains ten billion times the mass of Sun, but only 1% of this is hydrogen – the rest is dark matter.
Astronomers from UC Berkeley University have recently discovered a spiraling magnetic field in space, wrapped around a long, thin cloud of gas and dust called the Orion Molecular Cloud. The coiled magnetic field has pulled this gas cloud into a thin filament. Astronomers have suspected that magnetic forces can define the shape of interstellar clouds, but they haven’t seen evidence for it, until now. The Orion Molecular Cloud contains two stellar nurseries; one in the belt region, and another in the sword region of the Orion constellation.
The Orion Nebula is one of the most magnificent objects in the night sky, but it won’t last forever. Fortunately, astronomers now think they know where its successor will show up. A glowing gas cloud in the constellation Cassiopeia called W3 has just begun to shine with newborn stars. In just 100,000 years, it should be blazing in the night sky; just as the Orion Nebula fades from view. W3 was recently found to have a collection of massive protostars packed tightly together, eating away at a surrounding cocoon of gas and dust that obscures them from view.
An international team of astronomers have turned up an enormous companion galaxy to our Milky Way – it was hiding in plain sight. The star cluster is only 30,000 light years from Earth, and contains thousands of stars spread over an area 5,000 times larger than the full Moon in the sky. These stars don’t fall within the Milky Way’s spiral arms, galactic bulge or spherical halo, so astronomers figured they must belong to some other object. It’s probably the remnant from an ancient galactic merger.
A new instrument called Exoplanet Tracker has turned up an extrasolar planet orbiting a star 100 light years away. This instrument is designed to detect subtle shifts in starlight as a star moves back and forth through interactions with its planet. The Exoplanet Tracker is much cheaper than traditional spectrographs, costing only $200,000, and capable of being installed on lower power telescopes. Although this version can only watch one star at a time, future improvements should allow it to monitor 100 stars simultaneously.
According to new observations from the National Optical Astronomy Observatory, Vega appears to have a huge difference in temperature between its equator and poles. Vega is the 5th brightest star in the sky, completing one rotation every 12.5 hours. Its high rotation speed flattens out the star, so that it’s equator is 23% wider than its polar diameter. This result confirms the theory that rapidly rotating stars are cooler at their equators.
Polaris, or the North Star, is one of the most famous stars in the sky. But did you know it’s actually a triple star system? In a small telescope it’s easy to see two stars, but it took the massive resolving power of the Hubble Space Telescope to spot the third. By resolving this third star, astronomers hope to be able to accurately measure Polaris. This is very important because Polaris is a member of a special class of stars called Cepheid variables which are used by astronomers to measure distances.