* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Post Info
TOPIC: March 2010


L

Posts: 131433
Date:
Vernal equinox
Permalink  
 


Vernal equinox brings spring's early light in March

Spring starts at 1:32 p.m. March 20, according to the U.S. Naval Observatory. In plain terms, the vernal equinox occurs when the sun appears to cross the equator from the Southern into the Northern Hemisphere. But, of course, it is the Earth that is actually moving. The sun remains stationary. Remember, the Earth's pole is tilted 23.4 degrees and it is our planet that orbits the sun, giving us the illusion that the sun moves.
Scientifically speaking, the vernal equinox is defined when the centre of the sun's disc reaches the ascending node of the ecliptic on the celestial equator, according to the observatory.

Read more

__________________


L

Posts: 131433
Date:
RE: March 2010
Permalink  
 


march.gif

__________________


L

Posts: 131433
Date:
Permalink  
 

Highlights

Start of Spring
On the Vernal (Spring) Equinox, March 20th, the Sun moves north of the Earth's Equator. From the Vernal Equinox until the Autumnal Equinox, in September, the Sun will be in the Northern Hemisphere. On the Equinox, the Sun rises due East and sets due West. The festival of the Goddess Eostar, to whom the hare and the scarlet egg are sacred, takes place at the Vernal Full Moon.
From a very dark location at that time, look for the Zodiacal Light, a huge soft glowing column of light in the western horizon. It is the light of the Sun reflected off dust particles in the inner solar system. Its axis closely coincides with the ecliptic.

The Andromeda Galaxy
The great Andromeda Galaxy ("M31") is clearly one of the most glorious and resplendent of all deep-sky objects, and is visible in the northern skies until about midnight. At 2 million light years distant its regarded as the furthest thing visible to the unaided eye and is frequently called a sister galaxy to our own. Easily witnessed as a fuzzy elongated patch 4 degrees long (8 times the diameter of the full Moon), it is one of the most famous objects in our sky. Now take a few minutes and imagine being on a planet in M31, gazing up one evening and you would likely see our home as a ghostly-elongated patch high above in the alien skies. M31 was the first object positively identified as being located outside the Milky Way. Previously the Universe was thought not to extend beyond our own Galaxy, and the galaxies were felt to be disk shaped clouds of gas, possibly in the process of forming a new solar system like our own. This discovery in 1926 complete redefined our understanding of the Universe, its size and our place in it. When you find the galaxy, hold out your hand and cover it up. You have just hidden an estimated 300 billion stars and at nearly 200,000 light years across it is one of the largest galaxies known. The whole mass slowly rotates around the central hub; the core takes about 11 million years while the outer arms 90 million years or more. There is a small satellite galaxy, M32 that orbits M31 similar to our own Magellanic Clouds visible in the Southern Hemisphere.

Open cluster, M41
Within the constellation Canis Major, the great dog, is a splendid star cluster called M41. Located just south of Sirius (the brightest star in the sky next to the Sun), it is a large naked eye object of about 100 stars. The cluster is moving away from us at around 20 miles/second and is said to be about 20 light years across. This is one of the few deep-sky objects to have been recorded by the ancients, being mentioned by Aristotle around 325 BC.

The Crab Nebula, M1.
The famous Crab Nebula, M1. is nestled near the left horn of Taurus the Bull, you will find the Crab, so called due to its spindly, delicate appearance. Also known by the less romantic name of "M1", it was discovered in 1731, and is the remnant of the supernova of July 4, 1054 AD. Its hydrogen cloud is expanding at a rate of over 600 miles/second making it well over six light years across. M1 is home to one of the strongest x-ray sources known. Its source was traced to a neutron star, the first ever seen. A neutron star is the final remnant of a supernova which collapsed so tightly on itself that it is likely on the order of 6 miles in diameter yet with a density so great a single teaspoon full would be, well, really really REALLY heavy (on the order of a 1000 million tons). This discovery of the Crab Nebula's central star was the first visible evidence of such a peculiar beast and only happened when after first being detected by radio. As the star collapsed it picked up a spin, and as it would get smaller the spin rate would increase, not at all unlike an ice-skater who spins faster when she holds her arms in close to her body. Combine this with several other extreme conditions; radio energy was shot out of the poles much like a beacon from a lighthouse in the depths of the night. In this case the lighthouse was flashing us once every 1.33 seconds. At first some astronomers felt that this might be a sign of extraterrestrial intelligence, but more rational heads prevailed once the star was visually detected and seen to flash on and off. Since then well over a hundred of these "pulsars" have been discovered, one flashing of the incredible rate of 30 times a second! At ninth magnitude, the Crab is probably too dim to see with binoculars but is clearly visible in modest telescopes.



__________________


L

Posts: 131433
Date:
Permalink  
 

Watch out for sporadic meteors. Their rates for the Northern Hemisphere are now reaching a plateau. Expect around 12 random meteors per hour during the morning hours

You can listen to them by tuning to the 67 MHz meteor radar in Roswell, NM.

Shower Activity Period Maximum Radiant Velocity ZHR
Date R.A. Dec. km/s
Delta Leonids Feb 15-Mar 10 Feb 22 11:12
+16 23 2
Beta Leonids Broad Mar 4 11.0h 13.2 21.2 4.0
Alpha Virginids Mar 10 176 +9 2
Theta Virginids Mar 10 176 +9 2
Gamma Normids 11 - 22 Mar 11 16.7 -44.0 58.9 5.5
Gamma Virginids Jan 25 to April 15 Mar 25 12.0 5.7 22.2 4.6


__________________


L

Posts: 131433
Date:
Permalink  
 

Venus shines brightly low in the western sky as March begins. About 30 minutes after the Sun sets, look low on the western horizon to find Venus shining at a bright magnitude of -3.9. By the end of March, Venus is almost 12 degrees above the horizon 30 minutes after the Sun sets. On March 16, find Venus just to the left of a slender crescent Moon.
Read more

__________________
«First  <  1 2 3 | Page of 3  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard