APOD 2.5

 

This is a photo taken in Kansas of a "old" crescent moon, which refers to the length that the Moon has gone through a cycle of lunar phases starting from new.  Having just heard a presentation on lunar eclipses as a apart of the Solar System projects, I was interested in this image of the lunar occultation, a topic related yet separate from eclipses.  It is shown here occulting or passing in front of Mars , which is seen as a bright and tiny dot of light in the sky making it visible to the naked eye, which is rare.  At this point that the photo was taken the Moon is just about to set and appears very large due to its proximity to the horizon.  This picture is an exciting precursor to the total lunar eclipse that will be visible December 20th and 21st in North America, which occurs at the Moon's descending node in eastern Taurus, just four days before perigee, at 5:29 UT and ends at 11:04 UT.         

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.          

Observations

Last night at approximately 9:45 I stepped outsude to do some stargazing with my father.  We saw the teapot from the constellation Sagittarius as well as the constellation Scorpius to the left of the waning gibbous Moon.  Also I saw, almost directly overhead, the zig-zag shaped constellation Cassiopeia. At about 30 degrees to the right of the Moon I could see an extremely bright object, which I guessed to be the ISS since according to the heavens above website, it was supposed to be visible from my location. 

Obervations

Tonight at 11:00 I spotted the summer triangle and the Moon at waning gibbous.  Using my calibrated fist, I estimated the distance from Altair to the Moon to be about 9 degrees and saw that each star was roughly  6 degrees apart creating nearly equal sides.

APOD 1.8

     In this photo there appears to be a strange cloud formation above the sun and it has a noticeably more reddish tint than the yellowish orange surface of the Sun.  This extending loop is actually a solar prominence, which is an area of cooler plasma that allows for light to fall in the visible realm and therefore appears to have more saturated color.  Solar prominences are attached in the photosphere, the area where light is emitted, rather than the sun's corona, which is where the plasma is significantly hotter and made up of ionized gasses that do not emit very much light.  This particular solar prominence, captured by SOHO's Extreme ultraviolet Imaging Telescope (EIT), is the largest that we have on record. It was taken during a coronal mass ejection, which is caused by bursts of solar wind that come from the corona and as plasma is heated to the point that electrons are travelling at the speed of light, a rearrangement of the magnetic field occurs and creates a shock that accelerates the particles resulting in a solar flare.  When the solar flar occurs, gasses are released into space creating these loopy effects.  When a solar prominence is viewed staright on with the sun's surface as the background, they appear as dark sun spots because the cooler plasma does not appear as bright.            



Peurbach Biography

                 Georg Peurbach was born in the town of Peurbach, which makes his formal title Georg of Peurbach, in Austria.  Little information has been found on Peurbach’s early life and the first available record is his graduation from the University of Vienna in 1446 with a bachelor’s degree.  Peurbach received an education mainly in humanities and his knowledge of astronomy was acquired independently through access to the books and instruments of the deceased astronomer John of Gmunden who had taught at the university.   

Peurbach quickly became a fairly well recognized astronomer despite the fact that he had not yet published any material as he travelled through Europe through the years 1448 to 1453.  Peurbach delivered numerous lectures in major European cities and was offered a position to teach at both the university in Padua and at the university in Bologna.    Despite these generous offers Peurbach’s ambition motivated him to strive for more and he wanted to make serious scientific accomplishments rather than limiting himself solely to teaching.  Peurbach wanted to discover the exact positions of the Sun, the Moon and the planets in order to further develop astrology and use scientifically grounded charts to prove events in one’s future.  Astrology and astronomy worked harmoniously together in the fifteenth century despite today’s distinct division between the two studies.   

             Peurbach’s major opportunity came in 1454 when King Ladislas V of Hungary and of Bohemia, who was merely fourteen years old at the time, appointed him court astrologer.   Peurbach was also able to teach at the University of Vienna while serving as court astrologer, but he taught humanities rather than astronomy.  As a truly Renaissance man, Peurbach’s diverse academic background led him to write Latin poems written under a pseudonym When King Ladislas died in 1457 from leukemia after fleeing court to avoid political issues Peurbach was offered an even more attractive offer to become the court astrologer to the famous Holy Roman Emperor Frederick III.  Frederick III had a reputation for being a generous patron of the arts and sciences and specifically in the field of astronomy. 

         Regiomontanus, a student at the University of Vienna , collaborated with Peurbach starting in 1453 and the pair published numerous highly successful works for eight years.  Their first work was titled Theoricae Novae Planetarum, which is translated as New Theories of The Planets, in 1454.  The book detailed Peurbach’s theory on Ptolemy’s idea of planets’ epicycles in which he asserted that the planets motions are controlled by the Sun and are in the forms of solid and spheres.  Peurbach and Regiomontanus made observations on various eclipses and by measuring the durations of the eclipses they discovered that midpoint was eight minutes earlier than predicted by the Alphonsine Tables and translated these findings into an impressive set of calculation tables as well as measuring the obliquity of the ecliptic to be 23:28°.They both also made observations on the phenomenon later called Haley’s comet and created more detailed data tables.  Later Peurbach and Regiomontanus were working on a translation of the Almagest into Greek from the Arabic translation by Gerard of Cremonas upon request by the Greek scholar Bessarion.  However, Peurbach died at the age of thirty eight after only completing six books and on his deathbed he made Regiomontanus promise to finish the translation.  Regiomontanus followed through with his promise and the translation was published in 1463 and was dedicated to Bessarion.  Since Peurbach died at a relatively young age the question of what other discoveries he was capable of making is often  posed.        

APOD 1.7

NGC 2170 is a nebula, which is formed by the remnants of gas blown off by a star, located inside a molecular cloud.  More specifically it is located at the R2 iregion in the constellation Monoceros, or the unicorn as it is commonly called.  Monoceros is a relatively modern constellation formed in 1624 by the German astronomer Jakob Bartsch.  This photo of NGC 2170 was taken with the VISTA survey telescope, which is the largest in the world and is located at the ESO obervatory in northern Chile, in infrared since most new stars are hidden by thick interstellar gas that blocks visible and ultraviolet light and the low temperatures and high densities of the molecular clouds display the most visually appealing effects.  The tendrils and streamers of the nebula are created from interstellar dust by radiation emmitted from the stars and strong particle winds. 

APOD 1.6

This image is of the constellation Orion, or by its common name "The Great Hunter", with its Orion nebula (m42) and the Horsehead nebula located at the center of the sword.  The horsehead gets its dark hue from the interstellar dust which is composed of silicon, carbon and oxygen and when viewed at a greater magnification it truly does look like a head of a horse.  The reddish glow behind the dark head results from the ionization, the loss or gain of an electron, of hydrogen gas by the bright star Sigma Orionis.  The fade effect is created by streams of gas that are funneled by a strong magnetic field.  Also included in this picture is the Flame Nebula which is at the edge of the Orion molecular cloud and is made up of hydrogen gas ionized by a bright and young star that is a  a significant source of ultraviolet radiation.  

APOD 1.5

This picture of Saturn was taken by the Cassini spacecraft in February using infrared light, which is electromagnetic radiation that has longer wavelengths than visible light and is therefore undetectable to humans' eyes.  The picture's colors are artificial in order to make the infrared light visible to our eyes which is why this picture caught my attention and the blue coloration is derived from the Sun's light.  It depicts the auroras, or light displays in the sky at the polar regions that result from ionized nitrogen atoms regaining an electron, of Saturn which are more impressive than Earth's because the gaseous nature of Saturn creates a larger and powerful electromagnetic belt for these auroras to appear in.  Due to the strength of Saturn's magnetosphere, these auroras seen at the polar regions of Saturn are easily created by deflecting a stream of charged particles when they interact with its magnetic field.     

Astronomer Biography Sources

Georg Peurbach Bibliography

Complete Dictionary of Scientific Biography.  Vol. 15.  Detroit: Charles Scribner's Sons, 2008.  p473-479.

Schlager, Neil and Josh Lauer.  Science and Its Times.  Vol. 3: 1450 to 1699.  Detroit: Gale, 2001.  p305.

Robertson, E.F. and J.J. O'Connor.  "Georg Peurbach Biography."  University of St. Andrews, Scotland.  Aug. 2006.  <http://www-history.mcs.st-and.ac.uk/Biographies/Peurbach.html>  

APOD 1.4

 

This painting "Starry Night Over The Rhone" by van Gogh caught my eye since it is not actually a scientific photograph but rather an Post-Impressionist work of art from the nineteenth century.  I was drawn to this chaotic and colorful work as a person who has has an interest in art history and was curious to find out its astronomical significance.  

"Starry Night Over The Rhone" indicates an interest and understanding of astronomy by van Gogh since he sought to make the depictions of the stars fairly scientifically accurate over the French town Arles.  Although his more famous painting "Starry Night" does not contain any easily identifiable stars or planets, "Starry Night Over The Rhone" clearly depicts the two stars of the constellation Ursa Major, more commonly referred to as Big Dipper and the north star Polaris.  By estimating the line connecting the Big Dipper's stars to Polaris, the exact latitude of where this work was painted can be found which sounds to me like a nearly impossible feat and  proves his artistic talent even further than I had previously understood.   

APOD 1.3

The astronomy picture of the day for September 23 illustrates the autumnal equinox which occurs today at 3:09 UT.  The Moon is full and is called Harvest Moon, which means that the narrow angle to the ecliptic causes the moon to rise 30 minutes later each day rather than 50 minutes, creating the illusion that the Moon remains at its full phase for several nights. The equinox, which is the point where the ecliptic intersects the celestial equator,  marks the first day of fall and occurs when the angle between the Earth's axis and the sun is perpendicular.  The equinox results in 12 hours of daylight and 12 hours of night and a shorter time of darkness between sunset and moonrise which allowed farmers to gain a few more hours of work since they could see their crops in the moonlight.  The Harvest Moon appears orange to us because it rises at the horizon and it is here that the atmosphere is its thickets which causes more blue light to be scattered resulting in red light passing through our eyes.  

Lunar Observations 1.3

Tonight the Moon was full and the angular separation between the Moon and the planet Jupiter is about 9 degrees (observed at 11 PM).   This is 3 degrees more than my previous estimate but still follows the geeneral trend that the planets will appear to move westward as the moon move about 13 degress.

Lunar Observations 1.2

At tonight's star gaze at Turtle Beach I estimated that the angular separation of the Moon and Jupiter was 19 degrees looking east around 9:15 PM.  Based on the fact that the moon rotates at approximately 13 degrees per day, my prediction is that the angular separation bvetween the Moon and Jupiter will be about 6 degrees tomorrow night and I will make observations tomorrow to see if this is in fact true. Also I was able to see the teapot formation of stars in the constellation Sagittarius, the constellation Aquila and its first magnitude star Altair, Ursa Major or the Big Dipper, Scorpius and its first magnitude star Antares, Hercules and the keystone, Cassiopeia, and the summer triangle comprised of Altair, Deneb and Vega.  The planets Mars and Venus were visible to the naked eye and we were able to see Venus actually set into the horizon. 

Lunar Observations 1.1

The moon's phase tonight on September 19 at about 10:20 pm was waxing gibbous and very close to full moon.  The brightest object that was close to the moon was about 21 degrees due east of the moon which by my guess is the star Altair of the constellation Aquila. 

APOD 1.2

When the Moon and Venus converge the Moon appears at its faintest, since it is in crescent phase, while Venus actually appears at its brightest stage since in crescent phase the planet is relatively close to Earth.  This photo was taken in Spain at sunset which creates a remarkable photo because the two brightest objects in the sky have met together and stand out well even before the sky is dark.  This specific photo of the Moon and Venus converging, which happens  is especially unique because of the contrast created by the black birds, blue sky and the orange storm clouds.  However, these two objects only join for a brief time and after their seperation Venus continues to be seen at sunset for the rest of the month.  Today Venus rose at 10:30 AM and will set at 9:15 PM and will continue to rise and set a few minutes earlier as the days progress.      

APOD 1.1

APOD September 5

This incredibly dramatic photo provides evidence that, as pictured in the center, black holes or areas of highly concentrated mass with strong gravitational pulls, rotate in a formation similar to a whirlpool and are surrounded by hot swirling gasses indicated by red.  X-ray light is emitted as the gas swirls on the inner edge of the accretion disk, pulled inward by gravitational force, at a extremely high frequency caused by the rapid spinning of the black hole.  The most interesting aspect of this discovery is the fact that as these black holes spin they are pulling the actual fabric of space with them.  I wonder if the fact that black holes spin increases their threat to surrounding objects in space.