Jan Oort Biography

Jan Oort Biography

     Jan Oort was born April 28th 1900.  He died 92 years later on the 5th of November.  During his life time he contributed almost unmeasurably to the field of astronomy and remains an extremely well recognized astronomer even today.

     Oort is clearly most recognized for the aptly named Oort cloud.  This cloud is a hypothetical spherical cloud of comets that lie nearly a light year away from the sun. The outer edge of this belt of comets defines the outer limits of our Solar System.  The outer edge of the Oort cloud is gravitationally affected by passing stars and by the Milky Way Galaxy itself.  Although, currently, technology does not allow the direct observation of the existence of the Oort cloud, it is commonly accepted that this cloud is the place where all long period comets and Halley-type comets come from as they start there trip across our Solar System.  Oort postulated in 1950 that all comets come from the same place.  This was incorrect.  However, its principle is now accepted as fact due to this Oort cloud.

     Another very popular discovery that he made, which was actually more of a calculation, was his discovery that the center of the Milky Way lies 5900 parsecs away from Earth in the direction of Sagittarius.  He also showed that the Milky Way has a mass 1 billion times that of the Sun.  He also found that the Crab Nebula was polarized.  From this discovery he theorized synchrotron emission.

     Another thing that was named after Oort besides the Oort cloud was his calculated constants imaginitively named Oort's Constants.  These constants A and B are empirically defined paramaters or the rotationaly properties of our galaxy.  I would elaborate more on these extremely impressive foundings if I understood what they were.

     Many astronomers are very good at observation.  Many astronomers prefer calculated and applied astronomy.  Although Oort was clearly gifted at both it is obvious that he was more inclined to heavily mathematical and applied astronomy.

     The Dutch born astronomer's death marked the end of one of the great 20th century astronomer's life and consequently his extremely prolific discoveries.  After his death a colleague remarked "The great oak of Astronomy has been felled, and we are lost without its shadow."





P.S. I've been trying to get this to post all day long. Every time I have tried it won't let me. Hopefully this time it will go through.

APOD 4.8

The Little Dipper
2011 May 14

This is a picture of the very well known and very easily locatable asterism "The Little Dipper".  It is interesting to note that the Little Dipper is NOT a constellation.  It is in the constellation Ursa Minor.  Also, it is important to clarify that perheps the most popularly known star, Polaris, (maybe after Alpha Centauri) is not the brightest star in the sky.  It's actually not even close.  This asterism, or pictographic collection of stars, is easily seen and is circumpolar.  Polaris is actually the denotational star for the top of the sky.  This asterism spans 23 degrees across the night sky.

APOD 4.7

A Beautiful Trifid
2011 May 13

This is in space.  The fact that this beauty exists in space is interesting enough.  This is a Trifid Nebula. It is also known as M20.  It lies about 5000 light years from Earth in the nebula scattered constellation Sagittarius which lies at the center of our galaxy.  This picture represents three different kinds of nebulas (reflection, dark, and emission nebulae) all centered in this M object which is where it gets its name: Trifid.  It is about 40 light years across.

Zooniverse

I spent a total of four hours in the past two weeks on zooniverse doing moon zoo. I also started a little bit of solar stormwatch recently which is also interesting.

APOD 4.6

Globular Cluster M15 from Hubble
2011 May 3rd

Well, well, well....look what we have here. Another fantasticly appealing picture indicating an infinite number of stars in the universe.  If that many stars can be taken in one picture.....I digress. This picture is of globular cluster M15.  This cluster is visible even if all you're looking through is a pair i binoculars.  Recent evidence suggests that there is a massive black hole at its center.  And this cluster specifically is one of the oldest ones in the Milky Way Galaxy.  It occurs 35,000 light years away in the direction of Pegasus. And there has been a dramatic increase in the density of stars indicating that there is star formation happening in that region. This picture was taken by Hubble.