After what feels like an eternity of cloudy weather I got to see comet Holmes.
A bit of clear sky appeared , and the comet was just visible to the unaided eye here (the sky is heavily light polluted where I live).
Without any optical instruments it looks like a star to me - maybe it would be fuzzy in a darker sky.
Using a pair of binoculars at 15x magnification the comet is much like the pictures as seen here , with the exception of the faint green haze outside the brighter disk.
It looked bigger than I expected, and I noticed thet in order to get the most from the view, I had to use "averted vision" that is focusing the view a bit away from the comet. The brighter core is a little elliptic looking and a little offset from the centre of the disk.
If you have a pair of binoculars, you should go out and take a look. The Sky and Telescope link above gives you what you need to find the comet.
This is the third comet I have seen, only Hale-Bopp in April 1997 was bright enough to be clearly seen in the heavily light polluted skies of the western Netherlands, but this unexpected view is much better with a pair of binoculars , or better a telescope using a not too high magnification 20 - 50x should be fine.
Good luck comet hunting.
Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts
Monday, 29 October 2007
Thursday, 25 October 2007
Comet bursting into the sky.
Two days ago Comet 17P/Holmes was an insignificant piece of ice barely visible in amateur telescopes under dark skies.
Yesterday all that changed . If you have a clear sky, take a look in the constellation Perseus, there you will find an extra "fuzzy star" - visible to the unaided eye. With a visual magnitude og between 2.5 and 3 it should be about as strong as the stars in the "Big Dipper", "The Plough", "The big Wagon" or whatever you may call the most well known constellation in the Northern sky. The increase in brightness is about a million times in about 24 hours - quite amazing.
Take a look at Spaceweather.com for more information - and a star map to find the comet, and Cometography for a bit of history of this comet.
Stop Press: Latest estimates are now magnitude 2 .... even brighter ... so the outburst is still in progress.
Here's hoping for a little clear sky at my place i The Netherlands ...
Good luck with comet hunting.
Yesterday all that changed . If you have a clear sky, take a look in the constellation Perseus, there you will find an extra "fuzzy star" - visible to the unaided eye. With a visual magnitude og between 2.5 and 3 it should be about as strong as the stars in the "Big Dipper", "The Plough", "The big Wagon" or whatever you may call the most well known constellation in the Northern sky. The increase in brightness is about a million times in about 24 hours - quite amazing.
Take a look at Spaceweather.com for more information - and a star map to find the comet, and Cometography for a bit of history of this comet.
Stop Press: Latest estimates are now magnitude 2 .... even brighter ... so the outburst is still in progress.
Here's hoping for a little clear sky at my place i The Netherlands ...
Good luck with comet hunting.
Monday, 22 October 2007
Radio Astronomy and SETI
On 11 october a new radio telescope started operation. The Allen Telescope Array (ATA) in Hat Creek, CA is planned to be extended to an array of 350 dish antennas with a diameter of 6m (20ft) The inauguration was done with the first 42 of these dishes.
The ATA is built to do simultaneous radio astronmical observations and SETI work.
More detail can be found at the website for the SETI institute ATA ppress release.
I am quite excited, since the data collected from the ATA is *much* more than from traditional single dish telescopes , and more than will come from the VLA (Very Large Array) - and for a cost much loser than for older (traditional) radio telescopes.
For more about SETI (Search for ExtraTerrestrial Intelligence), take a look at at the websites :
SETI Institute
SETI League
SETI@home
The ATA is built to do simultaneous radio astronmical observations and SETI work.
More detail can be found at the website for the SETI institute ATA ppress release.
I am quite excited, since the data collected from the ATA is *much* more than from traditional single dish telescopes , and more than will come from the VLA (Very Large Array) - and for a cost much loser than for older (traditional) radio telescopes.
For more about SETI (Search for ExtraTerrestrial Intelligence), take a look at at the websites :
SETI Institute
SETI League
SETI@home
Thursday, 5 July 2007
Pulsar Measurements - Radio Astronomy Podcast
Just heard this on the podcast "Mountain Radio Astronomy". Their podcast of 8 October 2005 was an interview with pulsar hunter Scott Ransom at the National Radio Astronomy Observatory in Charlottesville. Scott had - at the time of the interview - found about 30 millisecond pulsars in a globular star cluster called Terzan 5.
A pulsar is believed to be a quickly rotating neutron star, a supernova remnant, most of them rotating in less than a second. The pulsar has a rather small and directional radiating area that can only be registered when it is facing us.
A second type of even faster rotating pulsars - known as millisecond pulsars - rotating more than a 100 tomes per second, are found in globular star clusters.
The rotation period of the millisecond pulsars is extremely precise, approaching that of an atomic clock , and this means thatsome interesting measurements of pulsar orbits can be made.
About 20 minutes into the interview he talked about a measurement of a pulsar orbit with an accuracy that really surprised me.
The example here is the Hulse-Taylor star system two pulsars orbiting each other in an orbit smaller than the Sun.This can demonstrate Einstein's general theory of relativity, the interaction between spacetime and gravitation and an indication of gravity waves.
One other of the pulsars, Terzan N is orbiting a massive companion in an almost exact circular orbit about the size of the Sun.there is a little eccentricity, that is difference in the long axis and the short axis of the orbit, is measured as 48 cm +/- 6 cm. Less than half a meter ! Measured at a distance of 20 000 light years. Mind blowing ...
Science stranger than fiction ...
Link to Mountain Radio Astronomy
Link to The podcast MP3 file
A pulsar is believed to be a quickly rotating neutron star, a supernova remnant, most of them rotating in less than a second. The pulsar has a rather small and directional radiating area that can only be registered when it is facing us.
A second type of even faster rotating pulsars - known as millisecond pulsars - rotating more than a 100 tomes per second, are found in globular star clusters.
The rotation period of the millisecond pulsars is extremely precise, approaching that of an atomic clock , and this means thatsome interesting measurements of pulsar orbits can be made.
About 20 minutes into the interview he talked about a measurement of a pulsar orbit with an accuracy that really surprised me.
The example here is the Hulse-Taylor star system two pulsars orbiting each other in an orbit smaller than the Sun.This can demonstrate Einstein's general theory of relativity, the interaction between spacetime and gravitation and an indication of gravity waves.
One other of the pulsars, Terzan N is orbiting a massive companion in an almost exact circular orbit about the size of the Sun.there is a little eccentricity, that is difference in the long axis and the short axis of the orbit, is measured as 48 cm +/- 6 cm. Less than half a meter ! Measured at a distance of 20 000 light years. Mind blowing ...
Science stranger than fiction ...
Link to Mountain Radio Astronomy
Link to The podcast MP3 file
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