APOD 3.8

Maybe déjà vu is real... Or maybe it's just deflections off of gravitational lenses. This is the first time a supernova explosion has been split into multiple images across intervening masses. The picture above is inside a galaxy cluster, taken in November by the Hubble Space Telescope. The multiplied Supernova, Refsdal, occurred in the universe far behind the cluster. Measuring the locations and time delays between images may allows astrophysicists to understand the amount of dark matter in not just the galaxy, but the cluster too. There is hope that a fifth image presents itself in the near future.

APOD 3.6

The most famous flower in the sky: The Rosette Nebula. The "petals" of the rose are actually stellar nurseries. The nebula is located 5,000 light years away within the Monoceros constellation. The symmetric shape is a result of the winds and radiation from its central cluster of hot, young stars. The stars are a part of the energetic cluster, NGC 2244. The stars are only a few million years old. The nebula is about 50 light-years in diameter. If you have a small telescope, you can see the nebula for yourself.

APOD 3.7

The Coma Cluster isn't just a collection of stars, it's a collection of galaxies; each with billions of stars inside it. The Coma Cluster is one of the densest know clusters, containing  1,000's of galaxies. Light from the Coma Cluster takes 100s of millions of years to get to Earth -the Coma Cluster is so big that for light to even get from one side to the other it would take millions of years. This 2006 image by the Hubble Space Telescope is just a small portion of Coma. Most of Coma's galaxies are elliptical, but there are also plenty that are spiral. Astronomers took interest into the Coma Cluster to investigate how galaxies in rich clusters form and evolve.

Johann Gottfried Galle (Essay)

Johann Gottfried Galle

Born in June 9, 1812, to J. Gottfried Galle and Henriette Pannier Johann grew up in the small German town, Dübener Heide. Galle attended school in Radis, Germany, and was then selected by local Clergymen for secondary school at Wittenberg. Galle studied at Wittenberg from April 1825 until April 1830, when he moved on to study at the Berlin Academy of Sciences. One of his teachers, Encke, would prove to be vital to his future. In 1833 Gall began teaching mathematics; in March the following year he was made assistant teacher at the Friedrich-Werder Gymnasium.  While still teaching secondary school, Galle kept in touch with his old educator, Encke. In 1835, Encke had become the director of the newly rebuilt Berlin Observatory, and invited Galle to be his assistant.

            Galle spent the next 16 years of his life dedicated to astronomy, more specifically astrometry. Galle was a dedicated observer of comets, including Halley’s Comet’s 1835 passing, Boguslavky’s comet, and Encke’s comet. In 1839 to 1840, Galle discovered three of his own comets –this feat attracted attention from both experts and royalty. In 1836, Alexander von Humbolt invited Galle to assist him in computing the astronomical material he had collected while on his journeys. For about 30 years, Galle also frequently did computational work concerning the minor planets, especially Pallas. In 1838, Galle observed the crepe ring of Saturn (though he did not publish this discovery).

            With government funding, Galle received his doctorate in theoretical studies on March 1, 1845. His thesis, Olai Roemeri triduum observationum astronomicarum, was based upon unanalyzed data from three days of meridian observations made by the Danish astronomer Roemer in 1706. Thinking the observations could be of value to Urbain Le Verrier, Galle sent him a copy. Le Verrier replied with the presumed position of a planet beyond Uranus –computed mathematically by Le Verrier and John Couch Adams from Uranus’s motion. Le Verrier did not have access to adequate telescopes in Paris, so he asked Galle to confirm his predictions. Galle was the first to see the planet, less than 1 degree from the predicted position. With his assistant Heinrich d’Arrest, Galle located the planet within the first few minutes of searching. Galle wrote, “I discovered a star of the eighth magnitude—not at first glance, to tell the truth, but after several comparisons. Its absence from the chart was so obvious that we had to try to observe it. Encke, who had been informed of all the details, took part in the observation on the same night. We observed the star until early morning; but, despite all duplications of effort, we did not succeed in discerning a definite motion, although a trace of change in the required sense seemed to occur. Full of excitement, we had to wait for the evening of 24 September, when our research was also favored by the weather and when the existence of the planet was proved”. The planet was at first named “Le Verrier’s planet” but was changed to Neptune to fit the Greek mythological names. Galle was modest about this discovery, refusing to capitalize from it.

            After the Neptune discovery, Galle continued his research in Berlin under Encke. Along with several other findings, Galle made several distance measurements of double stars. In 1847, Galle published a list of all comet orbits computed up to that time. Accepting an opportunity to start an independent career, Galle took the position of director of the observatory at Breslau. Galle continued his work in Breslau for 46 years. Galle taught all aspects of astrometry and meteorology. Though he dedicated most of his efforts to studying comets and planetoids, Galle became an avid lecturer who attracted large audiences. Galle found out that there is a relationship between the meteor showers recorded over the centuries and the appearance of comets. This led him to attempt computing the orbit of the Lyrid meteor shower around the sun to show its connection to Comet 1861 I. Galle successfully established the relation between meteor showers and the decomposition of a parent comet, which he classified as hyperbolic. Galle determined solar parallax by using corresponding data on minor planets. Although he specifically didn’t make the discovery, Galle’s methods were used to discover Eros.   

The poor equipment available at Breslau prevented Galle from making any pioneering discoveries. However, he was still able to participate in astronomical-geodetical tasks. Galle assisted in the determinations of longitude between berlin and Breslau. A streetcar line further limited his visibility and led him to turn to examining the magnetism of the Earth in relation to the Northern Lights and other terrestrial and even cosmic conditions. Galle went on to publish a series of works on climatology and weather forecasting. Later works by Galle dabbled in several minor matters in an array of fields.

In 1857, Galle married C. E. M. Regenbrecht, a daughter of a Breslau professor. Before she died in 1887, the couple had two sons. One, Andreas, went on to be an astronomer and geodesist at Potsdam. During his life, Galle received many honors and memberships to numerous scientific societies around the globe. Galle died in Potsdam, Germany on July 10^th, 1910 at the incredible age of 98. His teachings left his legacy far from over.

Planetary Nebulae

Name: NGC 6751 "The Glowing Eye"

Constellation: Aquila
Distance: 6,500 light-years
Size: 0.8 light-years
Other: Observed by Hubble in 1998


Name: NGC 6210

Constellation: Hercules
Distance: 6,500 light-years
Size: Unknown
Other: It contains stars similar to our Sun, in their final stages, giving us insight to the fate of our Sun


Name: NGC 6537 "The Red Spider Nebula"

Constellation: Sagittarius
Distance: 3,000 light-years
Size: Unknown
Other: This nebula contains one of the hottest stars in the Universe, and generates 100 billion kilometer high waves

Name: IC 4406 "The Retina Nebula"

Constellation: Lupus
Distance: 3,900 light-years
Size: 30 arcsec
Other: It is a symmetrical nebula

Name: IC 418 "The Spirograph Nebula"

Constellation: Lepus
Distance: 2,000 light-years
Size: 0.3 light-years
Other: Resembles a shape that could be made on a spiroraph -a toy which produces geometric patterns

Name: NGC 6853 "Dumbbell Nebula"

Constellation: Vulpecula
Distance: 1,200 light-years
Size: 8 x 5.7 arcmin
Other: one of the most photographed planetary nebulae in the night sky

Name: NGC 7293 "Helix Nebula"

Constellation: Aquarius
Distance: 700 light-years
Size: 16 arcmin
Other: one of the closest planetary nebulae to the Earth

Name: NGC 6720 "Ring Nebula"

Constellation: Lyra
Distance: 2,300 light-years
Size: 2.5 arcmin
Other: discovered by the French astronomer Antoine Darquier de Pellepoix in January 1779

Name: NGC 6543 "Cat's Eye Nebula"
 
Constellation: Draco
Distance: 3,000 light-years
Size: 25 arcsec
Other: first planetary nebula whose spectrum was investigated by the English amateur astronomer William Huggins, demonstrating that planetary nebulae were gaseous and not stellar in nature

Name: NGC 2392 "Eskimo Nebula"
 
Constellation: Gemini
Distance: 2,870 light-years
Size: 0.8 arcmins
Other: discovered by astronomer William Herschel in 1787