Slashdot Mirror
What Northern Hemisphere Astronomers Are Missing From the Southern Hemisphere
creimer (824291) writes The New York Times Sunday Review has an interesting article on the astronomical night life when viewed from Sao Paulo, Brazil, featuring a treasure trove not visible to astronomers in the Northern Hemisphere: "Yet the Southern Hemisphere claims the three brightest stars of the night sky: Sirius, Canopus and Alpha Centauri. Canopus belongs to the Carina constellation, notorious for two things: the Carina Nebula, four times as large and even brighter than the famous Orion Nebula, and the star system Eta Carinae, which is expected to burst as a supernova or hypernova sometime in the next thousand years. (A scientist told the BBC that the explosion would be so bright that you would see it during the day, and you could even read a book by its light at night.) Alpha Centauri and Beta Centauri, the 11th-brightest star, are called "The Pointers," as they form a line in the sky to the constellation Crux (the Southern Cross). Crux is the smallest of all 88 constellations but one of the most distinctive. It is visible at practically any time of the year in all of the Southern Hemisphere."
I mean, yes, it's true. And yes, it's interesting. But ... news?
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
...but, in terms of widely recognized asterism shape, Delphinus and Sagitta are both smaller. Sure, as the sky is officially divvied up and assigned to constellations, Crux gets the smallest area -- but those divisions seem about as respectable as gerrymandered congressional districts in the US.
Just to view the southern sky from the Atacama Desert. Clear skies far from light pollution. I need to see these sights. Those and the LMC and SMC.
The light pollution where I live is so bad that only a few stars are visible on a clear night. I frequently wish all the street lights could be turned off for a change. I doubt that the switch to LED street lights will improve things. In fact, I imagine it will make things worse for the local observatory (Lick) since it is relatively easy to filter out sodium.
This post is encrypted twice with ROT-13. Documenting or attempting to crack this encryption is illegal.
Yes, it's visible from most of the earth, with the only exception being really far north, north of the Arctic Circle. In the northern hemisphere it's considered part of the Winter Hexagon.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
Of course, the majority of humans now live in urban areas, and see little or nothing of the night sky at all, whether northern or southern. Perhaps I'm taking this a step too far, but would it be possible that we'll see a continuing decline in interest and support for astronomy and space technology as more and more voters and influential people grow up and live their lives without ever really seeing the skies?
Trust the Computer. The Computer is your friend.
And the wavelengths the LEDs are putting out - emission spectroscopy is what you are looking for.
One positive is a lot of the new lights have fittings that reflect the light more in the direction where it is useful. It's easier to design such things for lights that are not very hot.
Crux is very useful for navigating at night. From wikipedia:
In the Southern Hemisphere, the Southern Cross is frequently used for navigation in much the same way that the Pole Star is used in the Northern Hemisphere. Alpha and Gamma (known as Acrux and Gacrux respectively) are commonly used to mark south. Tracing a line from Gacrux to Acrux leads to a point close to the Southern Celestial Pole.[3] Alternatively, if a line is constructed perpendicularly between Alpha Centauri and Beta Centauri, the point where the above-mentioned line and this line intersect marks the Southern Celestial Pole. Another way to find south, strike line through Gacrux and Acrux, 3 1/2 times the distance between Gacrux and Acrux, directly below that point is south.
They sentenced me to twenty years of boredom
As you might imagine, there is a section specifically on Crux:
In your mind, draw a straight line through the axis of the Cross, through the tip and across the sky. You will find the arrow is pointing at another bright star. You cannot fail to identify this star, Achernar, because it is the only first-magnitude star in that part of the sky. Approximately halfway along the imaginary line between the cross and Achernar is the south celestial pole... Once you have established where the celestial pole is, you can determine your latitude. The celestial pole is always a number of degrees above the horizon equal to the latitude at which you are standing. Surprisingly, you don't need complex equipment to make this measurement. Polynesian navigators used a notched stick held at arms length, or sometimes nothing more than the outstretched hands and fingers.
Hej! Nasi tu byli!
Hey, you can do that up here too... as long as you don't mind freezing your balls off.
#DeleteChrome
The phrase "smallest of all 88 constellations" really irks me. Constellations aren't real things, they're imaginative descriptions of patterns people see to make it easier to remember which stars are which. There's at least one constellation "The Triangle*" which is smaller, or if you allow two-star constellations, "those two faint dots over there" is even smaller.
(*Yes, I stole that The Triangle from Terry Pratchett; it's the name of a Discworld constellation.)
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Heading south is a very good thing for astronomers to do. It's like visiting another planet: lots of new stars and stuff, and the familiar constellations are all upside down.
I've observed from Australia, New Zealand and the Cook Islands. My first view of the Eta Carinae region was from St. Kilda Beach in Melbourne. My first view of the Magellanic Clouds was from a highway rest area just south of Echuca, Victoria. One night at a motel in Forbes, NSW, I needed the bathroom in the wee hours and padded out to have a look. I knew the Sagittarius Milky Way would be out at that time of the night, but I couldn't find it at first. It was directly overhead.
Of course I went to Parkes. A nerd's gotta do what a nerd's gotta do. :-)
I'm watching Top Gear in Patagonia, and while Argentina has better scenery, Australia has better weather. And much better roads.
...laura
...that actual astronomers DO constantly use the equipment mounted in the southern hemisphere for observing.
Perhaps the article would have made more sense if instead of astronomers, she'd said 'stargazers' - people who just enjoy looking at stars as opposed to actual astronomers?
-Styopa
I submit that Triangulum, the triangle, does indeed look exactly like a triangle. So that makes at least two. The image of Orion, the hunter, is also very easy to visualize.
I do not know what you are talking about regarding the "name change" of the constellation Scorpius, it has been called that for all of the modern era. Are you confusing it with the astrological sign Scorpio?
I found it odd that the writer asserted that the only thing she missed from the Northern sky was the Big Dipper. She is also missing one of the most spectacular sights in the sky, M31 (the Andromeda galaxy), and also M33 (the Triangulum galaxy) - not as spectacular, but still the third largest galaxy in the Local Group to which we belong.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj