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View Full Version : Discussion: Pinpointing the Distance to a Pulsar



Fraser
2003-Aug-19, 09:53 PM
SUMMARY: Astronomers have used the accuracy of the National Science Foundation's Very Long Baseline Array (VLBA) to pinpoint the distance to a pulsar. The object, called PSR B0656+14, was previously thought to be up to 2,500 light-years away but it was at the same location in the sky as a supernova remnant which is only 1,000 light years away. This was thought to be a coincidence, but the new measurement from the VLBA pegs the pulsar at 950 light years away; the same distance as the remnant - they were both created by the same supernova blast.


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jkmccrann
2005-Dec-05, 05:08 PM
The only comment I would make is that that is a helluva differential! Thought to be up to 2500 ly away, but its now pegged at around 950 ly! Just shows we still have a lot to learn when it comes to measuring distance in Space and classifying objects to their true location.

jimmarsen
2005-Dec-06, 02:08 AM
What is the maximum distance that can be measured reliably with the VLBA?

Thanatos
2005-Dec-06, 09:18 AM
The VLBA is considered very accurate at least out to the ~20 million light year range. Not by the parallax method, obviously, but by luminosity. The science involved is rather complex, but, has very sound theoretical footings. The vexing problems presented by other luminosity models [e.g., Tolman surface brightness] do not come into play at this rather modest distance.