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Founded January 1970
Julian date: 2457689.16
"Every room looks clean in the dark."
THE DAILY ASTRONOMER
Wednesday, October 26, 2016
Mirror on the Milky Way
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CORRECTION!!
In yesterday's article, this dingbat wrote the following sentence:
"The part of Earth closest to the Sun (noon) experiences less gravity than the part farthest away (midnight.)."
Had I been a bit more careful, I would have actually written:
"The part of Earth closest to the Sun (noon) experiences MORE gravity than the part farthest away (midnight.)."
My sincerest apologies. -E.G.
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We return to Pandora's Jar, that mystical vessel tucked away somewhere in the star dome's deepest shadows. It is within this vessel that we store all the astronomy questions we receive from students, patrons, subscribers and others. Our aim, stated sometime in September when we were under the influence of demonic agencies, is to answer one hundred of these queries before the DA school year ends in early August 2017. Since that date is more than century in the future, we don't foresee any difficulty in achieving this goal. Today, we tick off two more Pandora parchments, bringing our total to seven! The first query conveys us deep into intergalactic space. The second brings us to our nearest dictionary.
Pandora Parchment # 6: You once said that astronomers can know how our galaxy appears by looking at other galaxies. Is there a galaxy that is believed to most closely resemble the Milky Way?" -Victor F, Norway
Hello!
Here it is:
You are now looking at an image of the galaxy NGC 6744, a barred spiral galaxy hidden within the constellation Pavo the Peacock. (See "From the Catacombs of Infinite Knowledge.") Even though this galaxy is more than 30 million light years away, astronomers are confident that NCC 6744 so closely resembles our own galaxy it looks like a mirror image of the Milky Way. The above image was captured by the European Southern Observatory through use of its Wide Field Imager. One can see the central "bar" from which issue a series of spiral arms that curl around the nucleus. Were we actually looking at an image of the Milky Way Galaxy, our Sun would be about 2/3 out from the nucleus, with the Orion "spur," a comparatively small structure within the galaxy's Orion'Cygnus Arm.
Pandora Parchment # 7: "Why do they call the month's highest tides 'spring' tides?"
-Linda Stoddard, Gorham
First, a quick review. The high tides that occur when the moon is either new or full -and, therefore aligned with the Sun- are called "spring tides." These are the highest high tides of the month. The high tides occurring when the moon is at either quarter phase -when the moon and Sun are operating perpendicularly to each other- are called "neap tides." These are the lowest high tides of the month. The word "spring" in this context has no relation to the seasonal spring. Instead, it derives from the German word "Springen," meaning to leap or jump. The word "neap" originates from an Old English word, "nep," meaning to lower.
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FROM THE CATACOMBS OF INFINITE KNOWLEDGE
"Pavo the Peacock."
FROM THE CATACOMBS OF INFINITE KNOWLEDGE
"Pavo the Peacock."
Far out of our sight, and adjacent to Octans, the constellation "containing" the south celestial pole, is Pavo the Peacock. One of the many constellations created by astronomer Petrus Plancius (1552-1622), Pavo is associated mythologically with the goddess Hera, who was said to have sailed through the firmament on a chariot drawn by peacocks. This constellation consists of a single peacock nestled close to the other "Southern Bird"constellations Grus, Phoenix and Tucans.
Pavo the Peacock A modern constellation devised by Petrus Planicius in 1597. Planicius developed this constellation and others based on observations recorded by Dutch navigator Pieter Dirkszoon Keyser. Unfortunately, Keyser perished on a mission in 1596. His recorded observations, however, gave rise to many constellations that still persist today. Image: Sky and Telescope