Talk:Crab Pulsar

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Given values for mass and radius[edit]

The values of mass and radius given in the table are based on reference [3]. However, the corresponding arXiv article is actually not about mass and radius estimates for the Crab pulsar. As far as I can see, it only assumes standard values for M and R, namely 1.4 M_solar and 10 km, and compares it to X-Ray observation to get information about the cooling behavior. In conclusion, the given values are just typical reference values for neutron stars in general, and do not represent any special estimates for the Crab pulsar. Either a different reference should be given, which really shows that these values are estimates for the Crab, or the values have to be removed.

Furthermore, it is inappropriate and misleading to express the radius in terms of the solar radius. — Preceding unsigned comment added by Matt.swift.hempel (talkcontribs) 13:22, 26 November 2013 (UTC)

I agree. Both this article and the one on Crab Nebula assign a definite value to the star's diameter, when the sources merely state the estimated diameters of typical neutron stars. The reference (#3) in Crab Nebula points to a web page that says 12 miles (20 km) but is itself referenced to a source that doesn't mention it. Doing a little digging, I figured out what it should have linked to (on the Chandra site). Sure enough, it said neutron stars are 12 miles (20 km), not this specific one. NASA used to say "the size of Manhattan" but now the use the phrase "no bigger than Manhattan." I found one source that said 100 picoarcseconds, but with no indication of how that figure was derived (maybe just an assumption). Working out the math (assuming a distance of 1999 parsecs) it comes out to about 29 km. So maybe we should find out if anyone is capable of measuring anything as small as 100 picoarcsdeconds (0.1 nanoarcsecond). Until then, we should remove these misleading statements. Zyxwv99 (talk) 20:28, 23 August 2014 (UTC)

Period citation[edit]

I can find several periods for the Crab pulsar but I haven't unambiguously found the first published period. I think the article should cite the first accurate measurement in the history section and the most accurate modern measurement in the introduction. Jason Quinn (talk) 21:01, 28 June 2008 (UTC)