APOD 2.4

 

This spectacular image was taken in Boulder, Colorado.  This APOD post intrigued me not only because I am applying to University of Colorado at Boulder, but also because this spotlight appearance of the sky actually occurred naturally.  The effect is created by the setting Sun's light projected onto the clouds, which are scientifically referred to as anticrepuscular rays.  Anticrepuscular rays converge in the opposite direction from the Sun, which is called the antisolar point or the point in the celestial sphere directly across from the Sun.  This effect is essentially an optical illusion based on perspective, similar to the converging lines of a long, straight road that appear to meet at one point,  These sun rays are actually parallel, but appear to converge at our horizon.  Without clouds blocking them, anticrepuscular or crepuscular rays, which have the opposite effects and converge onto the Sun, they can be easily spotted and are not rare but must be sighted at the right time.     

Observation Post

Last night at 9:35 I spotted the constellation Cassiopiea, the queen, which is circumpolar.  I estimated that it was roughly 30 degrees west of, referring to its distance, the nearly full waxing gibbous moon. 

APOD 2.3

 

Beyond this frosted leaf, the winter constellation Orion is highlighted.  This photo was taken in Japan and the twinkling effect on the stars, caused by Earth's atmosphere which distorts the light, is artfully replicated by the ice crystals on the leaf, making the constellation easier to spot to my eyes and more dramatic in effect.  However, this photo is made even more distinct because on the day it was taken, November 17th, a meteor sped by, which at this time of year are labeled the Leonids.  Additionally in the Constellation Orion, the giant star Betelgeuse (the reddish tinted star) can be seen.  Betelgeuse is large enough that it would stretch out to Jupiter's orbit if we replaced the Sun with it.  The other extremely bright star in this photo is Sirius, which happens to be designated as the brightest star in the night sky and has a magnitude of -1.46.  Sirius is actually a binary star, made up of Sirius A and B, but appears to the naked eye as one bright star.  Sirius is located in the constellation Canis Major, which is commonly called big dog.  Sirius was used by the Ancient Egyptians to mark the days of the flooding of the Nile and referred to the "dog days" of Summer for the Ancient Greeks.   

APOD 2.2

 

The image of this sparkling galaxy, called Centaurus A,was taken by the Hubble Space Telescope and is reminiscent of a  beautiful granite counter top.  This effect is due to the use of red, green and blue light to illustrate the large illuminated gas clouds and dark lines of dust that appear at its center.  Centaurus A is at a distance of 10,000,000 light years away from Earth.  Centaurs A is likely It has been labeled an active galaxy (and is the closest one to Earth) because it has a small core of emission far brighter than the rest of the galaxy and emits far more energy than is considered "normal".  Most of this excess energy is emitted as infrared, UV, radio and x-ray radiation.  Active galaxies, such as Centaurus A, often have massive black holes at their center.  Gravitational energy is released by the gathering of matter onto accretion disk that surrounds the black hole.  Infrared images of Centaurus A have shown that its black hole is capable of swallowing matter a billion times the mass of the Sun.  The ISO satellite has proven that there is another galaxy adjacent to Centaurus A and this other elliptical galaxy helps it retain its shape.      

APOD 2.1

 

These strange swirls on the sun looked like colorful brush strokes at my first glance.  They are actually spicules, which are defined as rapidly moving jets of plasma (superheated gas).  Taken last month, this photo happens to be the the highest resolution photo of spicules that we have and has spurred substantial scientific study since little was initially known about spicules from their discovery in 1877 to recent times.  Observation and study of spicules is made difficult by the fact that they move at 50,000 kilometers per hour and quickly disappear after 5 minutes, afterward regenerating another spicule from the same spot.  It is estimated that about 10,000 spicules are active on the Sun's corona at any particular time.   Their cycle is caused by when some some of the sound waves, which are mostly trapped on the Sun, escape and create shock waves that push matter forwards in the form of a spicule.  The current mystery posed by spicules to scientists is whether or not they contribute to solar wind, because it is possible that spicules provide some of the necessary mass to generate it.