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If you mean the previous claim of there being an Alpha Centauri Bb planet, later retracted, then this new finding involves a completely different star, not just
by WilliamDhalgren 10y ago
If you mean the previous claim of there being an Alpha Centauri Bb planet, later retracted, then this new finding involves a completely different star, not just a different period.
This is around Proxima Centauri, the previous one was around Alpha Centauri B. Proxima is a really really small red dwarf, just 12.3% the mass of sun, while Alpha Centauri B is a K-type star, ie somewhat smaller than sun but not that much; around 90% of Sun's mass (And there's also Alpha Centauri A, 10% more massive than the sun). We're not even 100% sure that Proxima is part of the Alpha Centauri system, though I gather it's considered highly likely - it's pretty distant from the Alpha Centauri system, some 15 000 AU (1 AU = distance between Sun and Earth), almost a quarter of a light year.
- taliesinb 10y agoYes, realized this and was editing my comment to reflect that but you beat me to it :). They did mention a previous signal from 2013, which got me confused with the spurious signal the SETI lecture mentioned.
- WilliamDhalgren 10y agoheh, as you say; apparently there was a previous signal; reading the article about the find at centauri dreams, http://www.centauri-dreams.org/?p=36210 http://www.centauri-dreams.org/?p=36210 - and it does mention a pre-2016 Doppler signal with a period of 11.2 days around specifically Proxima, that was unconfirmed, and that this mission was to investigate that more closely. "The HARPS Pale Red Dot campaign was created to confirm or refute this 11.2-day signal" I'm just not sure if that's what the speaker in your video was talking about, of if the embarrasing mistake that was actually announced was the Alpha Centauri Bb planet (or maybe there were other candidates I didn't hear about); I'm gonna watch the lecture you linked and see. Thx for an interesting link, btw!