Talk:Kepler-1649c

Possible Errors in Orbital Parameters

There's something wrong with the orbital parameters for Kepler 1649c. They lead to very inconsistent estimates for the mass of Kepler-1649 star.

Mass of star Kepler-1649 calculated, using Kepler's Third Law, from the Exoplanet.eu website's orbital parameters for Kepler-1649b:

M = 4π²a³ / (P²G)

a³ = (0.0514 AU)³ = 4.546e+29 m³

P² = (8.68909 d)² = 5.636e+11 sec²

4π²/G = 591498997713 kg sec² m⁻³, CODATA 2018

M = 4.771e+29 kg = 0.240 M☉

That result is in the right ballpark. The official estimate of Kepler-1649 star's mass is 0.219 M☉. However, that can't be said of the mass for the star calculated from the orbital parameters of Kepler-1649c.

Mass of star Kepler-1649 calculated, using Kepler's Third Law, from Wikipedia's orbital parameters for Kepler-1649c:

M = 4π²a³ / (P²G)

a³ = (0.0649 AU)³ = 9.152e29 m³

P² = (19.5352551 d)² = 2.849e12 sec²

4π²/G = 591498997713 kg sec² m⁻³, CODATA 2018

M = 1.90e+29 kg = 0.0956 M☉

Either the semimajor axis or the period, or both, reported for Kepler-1649c is wrong.

On the assumption that

M = 0.240 M☉

P = 19.5352551 d

Then the correct value for the semimajor axis of Kepler-1649c's orbit would be about 0.0882 AU.

On the assumption that

M = 0.219 M☉

P = 19.5352551 d

Then the correct value for the semimajor axis of Kepler-1649c's orbit would be about 0.0856 AU.

184.15.22.117 (talk) 16:40, 27 April 2020 (UTC)

@184.15.22.117: Do you have a reliable secondary source stating the correct figure for Kepler 1649c's orbital parameter? Wikipedia articles rely on secondary coverage and not on original research.  Versace1608  ^{Wanna Talk?} 17:11, 27 April 2020 (UTC)

Do you mean whether I have an authoritative news source from whom I reached the conclusion that the published value for the semimajor axis of Kepler-1649c's orbit is probably too low? No, I don't. I was trained to do this kind of calculation for myself, and it is original research. I presented the equation for Kepler's Third Law so that anyone trained in math through high school algebra could check my result. If my talk-comment violates Wikipedia's policy, then please remove it. — Preceding unsigned comment added by 184.15.22.117 (talk) 17:46, 27 April 2020 (UTC)

@184.15.22.117: I am not questioning your calculations. You seem very knowledgeable about what you're saying and I'm confident your calculations are accurate. Having said that, Wikipedia relies on reliable secondary sources. If you do not have an authoritative reliable source, you cannot modify the orbital parameters.  Versace1608  ^{Wanna Talk?} 19:58, 27 April 2020 (UTC)

The problem with your no-original-research policy is that these journalists, whom you ironically call "authoritative," lack the acquired science sense to know when something in the numbers he's putting in his narrative smells off. If he makes a typo and doesn't catch it right away, then it could get into publication. And then almost everyone downstream of him (such as Wikipedia) will post this nonsense, insisting all the while that it is authoritative, hence presumably reliable. This doesn't work well with science. Indeed, it doesn't work well with truth of any sort.

The discovery paper for exoplanet Kepler-1649c can be found here. The values for the mass of star Kepler-1649 and for the orbital radius of exoplanets b and c, are plausible and are mutually consistent. The inaccurate numbers that I noticed on other websites were likely the result of one of your authoritative news sources making a typo, and subsequently being copied by others. — Preceding unsigned comment added by 184.15.124.85 (talk) 17:28, 29 April 2020 (UTC)

@184.15.124.85: Wikipedia articles are only as reliable as the sources they are citing. If a source contains erroneous info, the Wikipedia article citing that source will also contain the same erroneous info. However, since Wikipedia articles can be edited by anyone, the erroneous info has a chance of being corrected immediately or in the near future. If you have a reliable source that validates the numbers you derived, feel feel to update the article and include the source in your edit. Please be careful with your tone; I won't call what they're posting "nonsense" if i were you. Some of these sources are highly reliable sources.  Versace1608  ^{Wanna Talk?} 17:48, 29 April 2020 (UTC)

Does the original discovery paper count as a reliable source? From what I've read about authoritativeness and reliability in the past on Wikipedia, it might be considered original research. However, the paper did travel through the vetting of the editors of the Astrophysical Journal, so perhaps that satisfies the requirement that Wikipedia's notion of authoritativeness seems to hinge upon. It isn't as though the authors of the paper were speaking directly to Wikipedia's page for Kepler-1649c, but rather went first to a well-respected publisher of scientific papers and gained that publisher's approval. So perhaps the original discovery paper would count as a reliable source, after all. — Preceding unsigned comment added by 184.15.124.85 (talk) 18:38, 29 April 2020 (UTC)

@184.15.124.85: This article published in the American Astronomical Society is definitely reliable. Peer-reviewed scholarly journals like these take precedence over newspaper sources. Please make sure you cite this source when you make changes to the article. As long as this source corroborates your calculations, your edit would be warranted.  Versace1608  ^{Wanna Talk?} 22:06, 29 April 2020 (UTC)