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Cecilia Payne-Gaposchkin discovered that stars are mostly made of hydrogen

Cecilia Payne-Gaposchkin discovered that stars are mostly made of hydrogen

_Microft

Comments (53)

  • chasil
    Two other women who have made similar profound impacts upon astronomy are Henrietta Swan Leavit (who discovered Cephid Variable stars, which are used as "standard candles" for distance measurement), and Jocelyn Bell (who discovered the pulsar class of neutron stars).https://en.m.wikipedia.org/wiki/Cepheid_variablehttps://en.m.wikipedia.org/wiki/Pulsar
  • perihelions
    The theory that hydrogen fusion powers stars is actually older than the discovery that the sun is made of (mostly) hydrogen. Eddington proposed it in 1920. It wasn't necessary to assume a "mostly hydrogen" sun—his estimate was that a >5% hydrogen sun would be sufficient.https://sci-hub.se/10.1126/science.52.1341.233The immediate historical motivation wasn't the discovery of hydrogen in the solar atmosphere, but the discovery, on Earth, that the hydrogen atom is anomalously heavy (~1% mass excess per nucleon).
  • somat
    I went down an interesting rabbit hole recently, I was trying to figure how big the iron core of the sun was and the answers were surprisingly all over the place.There is the no iron core/fractional percentage gang which bases their theory on the observed sun, but this conflicts with the common cloud theory of solar system origin, which is basically there was enough iron in the proto cloud to provide iron cores for most of the inner planets and you are telling that you think that most of this iron did not end up in the middle of the sun.then at the far end of the spectrum is the crackpot "the solar system is a second generation(minimum) system, some star must have exploded to form the metals we see, the core of the sun is probably the stellar remnant of the first generation system and is mostly iron"But really I wonder, all our observations of the sun are of the upper atmosphere, and more importantly the light emitted by the upper atmosphere, if earth was observed the same way you would conclude it was mainly made of nitrogen.
  • timthorn
    A new play based on her life has just opened in London: https://www.hampsteadtheatre.com/whats-on/2024/the-lightest-...
  • _Microft
    There is also a substantial article on Wikipedia about her if you want to know more:https://en.wikipedia.org/wiki/Cecilia_Payne-Gaposchkin
  • renox
    Thanks, I didn't know about her which is a shame because her discovery is Nobel worthy..
  • seanhunter
    She has a patera (volcanic crater) on Venus named after her https://planetarynames.wr.usgs.gov/Feature/4623
  • 082349872349872
  • chasil
    ...unless they are (massive enough to be) at the other end, the "silicon burning phase."Don't blink.https://en.m.wikipedia.org/wiki/Silicon-burning_process
  • black_13
    [dead]
  • netcoyote
    Record levels of solar-related deaths this year spawned calls for increased research of the sun to identify potential solutions, with some groups calling for sun-related regulation to reduce the shockingly high death tolls, including those related to heatstroke and famine, as well as longer-term issues including skin-cancer. Hurricanes are also considered a major issue given their proximity to the Capitol.Also at issue is the large amount of the chemical element hydrogen which makes up the sun, which is a significant fire hazard, though some in the scientific community downplay its risk.The issue is expected to be especially significant in this election year.Left-wing politicians in Congress are calling for more sun research funding to provide greater clarity on the issues facing voters, though several of their more extreme members have already introduced competing bills to the House floor with proposals to reduce solar intensity, increase shielding around at-risk neighborhoods, or mandate warning labels in key locations.Conservatives members of Congress deny that the sun is a significant source of risk, or in the event that it is an issue, that Congress should enact legislation to address the problem. "US citizens are aware of the risks, and should be able to exercise their god-given rights to do as they please in the sun."On the far right end of the spectrum the senator from South Florida has introduced legislation to reclassify hydrogen as helium, an inert gas that poses no burn risk, and has industrial and commercial uses that would be a boon to US industry.The senator was quoted as saying, "We've got to prevent foreign helium from undercutting the US market, and so my bill would radically increase the supply of this critical element used in birthday balloons while protecting US jobs from unfair competition." The senator had no comment about reports of contributions to his campaign from the American Society for the Suppression of Helium, Oxygen, and Lithium in Energy imports./s