Friday, April 27, 2012

Astronomy Cast- Big Dipper

When looking at the big diper there is the bowl, and then moving away from the bowl, you have the three stars that make up the handle, and the middle star. When you say double star, that’s just two stars that appear close together. These aren’t stars that are orbiting one another or anything like that, but it does qualify as a widely-spaced double star. Now, the thing is these stars, if you keep looking at them better, they then split themselves apart again, making this a quadruple system because each of them are independently binary systems.  So, while they are both double systems, you can’t actually split both of them. It’s one of those unfortunate things where Alcor. it’s a spectroscopic binary, so if you look at it with a big telescope attached to a spectrograph, watch it over time, you see the lines dancing apart from the two different stars, but with your standard backyard system, you’re not going to split it into two different stars. Mizar, on the other hand, all you really need is clear skies and a really good eyepiece on even a small backyard telescope, so I’d say pull out your handy dandy friendly 70 mm refractor and a 4 mm eyepiece, if your sky supports it, and you should be able to split those.  So that is one of the brightest stars, but we’re used to thinking of constellations as politely being: alpha’s the brightest, beta’s the next, gamma’s the next, but with this particular constellation, they actually labeled things right to left and sort of didn’t worry about what was the brightest or not, so if you want to keep track of which is which, you start at the upper right-hand star and go around in a clockwise direction and you get alpha, beta, gamma, delta as you go around. So yeah there’s a bunch of stars, they’re not individually as spectacular as the stars in Orion. In Orion you have Betelgeuse and Rigel and it’s a party, but in The Big Dipper, Ursa Major, really it’s about the objects that are clustered around the constellation itself . Many of the most famous Messier objects. ones that you all recognize looking at pictures from Hubble. are all located in this one constellation.

Astronomy Cast- Orion

Other cultures see Orion as three sisters instead of three belt stars, and so they make up all sorts of different stories based around this set of bright stars that hangs out near the celestial equator, and it’s basically a giant box wearing a belt, and so parcel up that giant box however you want it. In western lore it’s typically Orion the Hunter. Here in the northern hemisphere, the two stars you see generally pointing toward zenith are seen as the shoulders — and one of these is the bright-red Betelgeuse — and he’s seen as either holding up a sword or sometimes holding up a shield as he fends off the oncoming Taurus the Bull. So, it’s one of those constellations that people tend to turn all different sorts of things out of it. In fact, you can sometimes even see him in some of the drawings looking away from Taurus the Bull as Taurus comes up behind him. Most of the stories agree upon is Orion was a hunter, and he had a run-in with Scorpio, the giant scorpion, and after they both died, they got put into the heavens but on opposite sides of the sky, such that Scorpio is up high in the sky six months before Orion is up high in the sky. Rigel, is hundreds of light years away, and the nearest star in the constellation is just 18 light years away. So, we have this vast disparity in the difference between the nearest and the brightest stars, and if you’re able to make a 3-dimensional map of this it actually shows this fabulous distance distribution even of the belt stars. So this is just a group of stars that appear lined-up, but that’s only because they happen to randomly be collected in 3-dimensional space in the same direction on the sky. And so this is where you end up with interesting things like Betelgeuse appears amazingly bright. It is amazingly bright, in fact it’s about 670 times the size of the Sun, so this is a giant, red, bright, huge star, and it’s about 640 light years away.  So this is a giant star; it has a puffed-out atmosphere. This is one of the stars in the sky that’s most likely to go supernova in our lifetime – that doesn’t mean it will, that doesn’t mean it will even do it in the next 10,000 years, but it’s still sitting there waiting to potentially do it, and if this giant, red star does go supernova, it will actually be visible for almost the entire planet during the daylight.


Tuesday, April 24, 2012

APOD 4.4


M57, The Ring Nebula is probably the most famous celestial band. Its classic appearance is understood to be due to perspective - our view from planet Earth looks down the center of a roughly barrel-shaped cloud of glowing gas. But expansive looping structures are seen to extend far beyond the Ring Nebula's familiar central regions in this intriguing composite of ground based and Hubble Space Telescope images with narrowband image data from Subaru. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from the dying, once sun-like star at the nebula's center. Intense ultraviolet light from the hot central star ionizes atoms in the gas.

APOD 4.3


they all occur in the constellation of the unicorn Monoceros. Pictured above as a star forming region cataloged as NGC 2264, the complex jumble of cosmic gas and dust is about 2,700 light-years distant and mixes reddish emission nebulae excited by energetic light from newborn stars with dark interstellar dust clouds. Where the otherwise obscuring dust clouds lie close to the hot, young stars they also reflect starlight, forming blue reflection nebulae. The above image spans about 3/4 degree or nearly 1.5 full moons, covering 40 light-years at the distance of NGC 2264.

APOD 4.2

 What this picture is focusing on is no tourist destination but the celestial triple conjunction of Venus, Jupiter and the Moon which I personally saw from my gf's house near the same time that night. This spectacular beauty was seen by the Western Hemisphere and appreciated world wide for its unsual and beautiful appearance. Jupiter is near the moon and Venus is the brightest object in the night sky, looming above both the moon and Jupiter.

APOD 4.1


On March 27, five rockets were launched from NASA's Wallops Flight Facility in Virgina. The Anomalous Transport Rocket EXperiment  began launching at 4:58 am and launched these rockets at 80 second intervals. The chemical tracer that comes out of the rockets releases white clouds within Earth's ionosphere. These cool clouds were seen along the mid-atlantic region of the U.S. as the clouds drifted across the starry sky. This magnificent photograph was captured in New Jersey and the constellations visible in the background include Sagittarius and Scorpius with Antares also visible in Scorpius.