APOD 2.1- It Came from the Sun

The large cloud of dust that appears to be extending off of the surface of the Sun is what is called a prominence.  Solar prominences are enormous clouds of gas that  are held  near the Sun by its magnetic fields. A quiescent prominence last about a month, whereas an eruptive prominence  will erupt much more quickly. The expulsions of hot gas seen in the photograph are eruptive prominences. Prominences appear darker than the Sun because they are slightly cooler than its surface. This particular one (seen on the top right side of the Sun in this photo) is the largest one yet on record. It is large enough to fit the mass of Earth inside of it.

APOD 1.8-Globular Star Clusters

In the vast, starry area known as the Milky Way, globular star clusters are extremely common. Within these clusters, several hundred thousand stars are gravitationally held together in one large group. The stars within the clusters of the Milky Way are estimated to be up to billions of years old. This gives astronomers more information about the age of the Universe. This particular cluster, found in the constellation of Delphinius, is the cluster NGC 6934. It was discovered in 1785 by William Herschel, has a magnitude of 8.83, is 10 billion years old and is 50,000 light years away from our earth.

Christoph Clavius Biography

Christoph Clavius

Christoph Clavius was born in Bamberg, Bavaria on March 25, 1538 and died on February 2, 1612 in Rome, Italy. His life’s work was devoted to practicing mathematics and astronomy. It is suspected that he changed his name from a German name, possibly 'Schlüssel', which means ‘key’, to the Latin name ‘Clavius’ which also means ‘key’. Clavius was a member of the Jesuit Order, where he received his education and was sent to University of Coimbra in Portugal in 1556. He became a Professor of Mathematics at Collegio Romano in 1565, while still a student of theology. He published several books, the most well known one being The Elements of Euclid.

Gregorian Calendar

Although his primary studies were in the field of mathematics, his observation of the solar eclipse in 1560 inspired him to pursue the study of astronomy. His first and most significant astronomical achievement was his reformation of the Julian calendar (which came to be known as the Gregorian calendar under King Gregory XIII) and the establishment of functioning leap years. Since the Gregorian calendar used a more accurate value for the tropical year than the Julian calendar used, Clavius used its concept of omitting centennial years to correct the calendar, which became known as the solar correction. He proposed the rule that leap years occur in years that are divisible by four, except years ending in ‘00’ must be divisible by 400. We still use this rule today. Clavius met with Galileo in Rome in 1587, and the two occasionally corresponded from that day onward. Clavius confirmed Galileo’s discoveries, however, he did not confirm Galileo’s theory. As an astronomer, Clavius supported the Ptolemaic system and strongly opposed Copernicus. His development of the modern calendar is extremely significant, although it is greatly overlooked today.

APOD 1.7-Horsehead and Orion Nebulas

The Horsehead nebula (also called Barnard 33) is part of a massive, dark molecular cloud, located in the constellation of Orion. The nebula glows red as hydrogen gas is emitted by Sigma Orionis, which is located behind the Horsehead. A blue glow is also behind the nebula, coming from a reflection nebula called NGC 2023. Reflection nebulas give off light because they reflect the light of a nearby star. In the midst of the red and blue glow, the Horsehead shape is formed in a dark, black cloud of dust. Interstellar dust blocks out light, leaving the appearance of a dark hole in the nebula. Light from the Horsehead nebula takes approximately 1,500 years to reach Earth.

Great Orion Nebula in bottom right and Horsehead nebula in top left.

APOD 1.6- Auroras of Saturn

In order to investigate why auroras occur on Saturn scientists have looked at many infared photos of the planet previously taken by the Cassini spacecraft. Auroras can occur and are effected depending on Saturn's rotation and the angle of the Sun. Saturn's moon can also effect the auroras taking place in the magnetosphere, which like Earth's, deflects the solar wind particles being emitted by the Sun. The angle of the solar wind particles coming from the sun and the rotaion of Saturn will tell where the particles will be deflected on Saturn's surface. However, Saturn's auroras can occur over an entire pole, as opposed to merely the magnetic poles, where they happen on Jupiter and Earth. Saturn reflects a glowing red, while its ring appear to be a very bright blue as they reflect the most light from the Sun.

Observation 2

Location: Blackburn Pt. Rd.
Time: 8:30-9:30 P.M.

Last evening was extremely clear and wonderful for stargazing. The moon is in its third quarter, so it was not yet in the sky which made it even easier to see the constellations. I went to the stargazing session with my class and got the chance to look at the stars and planets with binoculars and a telescope. Jupiter was very bright in the sky towards the southeast and through telescope, its moons were visible as well. Vega was also shinning brightly overhead and I could spot summer and fall constellations such as Ursa Major, Scorpius, Pegasus, Saggatarius, and Lyra. However, around 9:00 something very unexpected occurred, as a "falling star" or meteor shot across the sky toward the northeast. It only lasted a few seconds before it disappeared, but nonetheless, it was spectacular!