Here's the latest article from the Astronomy site at BellaOnline.com.
Cosmic Ghosts, Ghouls and Vampires
Astronomers use colorful language for cosmic objects. But unlike ghosts, ghouls and vampires in horror stories, the cosmic ones aren't scary late at night. Here are tales of the birth, evolution and death of stars, a blinking demon and a star that, at Halloween, seems like the Sun's ghost.
*Scale in the Universe*
Last week's article dealt with the idea of choosing measuring units that suit the the scale your working at. Here is a very good graphic strip that shows changing scale in the Universe. It takes you from Earth to the observable Universe. Think carefully about each increase in scale to appreciate what you're seeing. (But not so carefully that it gives you a headache!) http://www.pinterest.com/pin/250090585531248883/
*Solar Eclipse next weekend*
There is a hybrid solar eclipse on November 3 - it begins as an annular eclipse, then becomes total. Some people in the eastern USA and Canada could see a partial eclipse at sunrise, but the path of totality goes across the Atlantic and through central Africa.
(1) Here is a map of the eclipse path: http://media.skyandtelescope.com/images/CC_Nov13_EclipseGlobe_l.jpg.
(2) This map shows what people in North America might see: http://eclipse-maps.com/Eclipse-Maps/Gallery/Pages/Annular-total_solar_eclipse_of_2013_November_3_files/HSE2013_Americas.png.
(3) Here are some sample timings: http://media.skyandtelescope.com/documents/OH2013-Tab04.pdf. The times are all in UTC, so you need to adjust them for your time zone.
If you're able to view the eclipse, remember your eclipse glasses and to ensure all optical equipment has a correct solar filter fitted to the front of it.
You can learn more about solar eclipses here: http://www.bellaonline.com/articles/art28395.asp.
*Paul Murdin vs Dan Brown*
I don't know if you've read “The Da Vinci Code”. I haven't, but Paul Murdin has. In fact, he says it inspired him to research and write “The Full Meridian of Glory”. Of course, Brown's book is fantasy, but he claimed that for the parts of the book that weren't plot: "99 percent of it is true. All of the architecture, the art, the secret rituals, the history, all of that is true."
Murdin (and others) have taken exception to this. For example in the book Brown writes of the church of Saint-Sulpice that there is "...a thin polished strip of brass glistened in the stone.... It was a gnomon, ... a pagan astronomical device like a sundial. ... "
But a gnomon is simply the bit on a sundial whose shadow shows the time. In Saint-Sulpice the obelisk is the gnomon and the brass line is a meridian - a line oriented north-south. It's an astronomical device, but not pagan. It was installed in the church by Languet de Gergy (1675-1750) who was the priest there. It was to help determine the date of Easter, which needs accurate solar observations. Here is a picture: http://www.pinterest.com/pin/250090585531264093/.
For a variety of astronomy images, follow me on Pinterest at: http://pinterest.com/astrobella/
To participate in online discussions, this site has a community forum all about Astronomy located here - http://forums.bellaonline.com/ubbthreads.php?ubb=postlist&Board=323
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I wish you clear skies.
Mona Evans, Astronomy Editor
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