Talk:Regulus

Revert explanation

I restored the Star Trek reference. Yes, "Encounter at Farpoint" took place at "Deneb IV". However, Deneb is used inconsistently in Star Trek: the episode clearly could not take place at the star we call Deneb, which is between 1600 and 3200 light years from Earth. Even if it is 1600 light years away, at warp 6 it would take 4 years to reach; even at warp 9.99 it would take over six months. The semi-canon Star Trek: Star Charts identifies "Deneb IV" as corresponding to our "Alpha Leonis IV", which makes it the fourth planet of the Alpha Leonis, or Regulus, system. If my analysis is incorrect or flawed, please let me know. — Knowledge Seeker দ 02:39, 15 July 2005 (UTC)

"semi-canon"

No analysis is needed. "Star Trek" is fictional. They said very clearly "Deneb IV". Your point may go over well with involved fans, but the casual viewer hears "Deneb IV" when watching "Encounter at Farpoint". You are attempting to retcon the episode, which is beyond the bounds of this encyclopedia entry. Your points should be made in a Star Trek specific forum.

If you still feel the need to include the reference, the entry deserves a qualification that "Deneb IV" is the specific name mentioned in the episode, but fanfic writers believe Regulus fits the continuity of the series better.

Ah, nevermind.

I'll add the qualifier myself.

Persians in 3000BC????

Thats something new!!! I don't understand why astrology keeps being mixed with astronomy... 91.92.176.184 07:24, 29 April 2007 (UTC)

I don't know why either, since astrology is pseudo-science. Star Trek references are about the same value. Anyway, I tightened up the article and put the 'cultural' stuff where it belongs. 68Kustom (talk) 00:56, 18 February 2008 (UTC)

In /dev/null then? Said: Rursus (☻) 21:49, 15 December 2008 (UTC)

On the Royal stars page, which is apparently the four stars, including Regulus, the "3000 B.C. Persians" used, there was a comment from another user that states this is impossible because Persians are only recorded in history starting 2000 BC - 500 BC, which corresponds to when they game to present day Iran. I checked the article Persian people, and this other user is correct. Can anyone find sources for this? SkarmCA (talk) 17:14, 18 December 2008 (UTC)

Too long intro

The intro could be shorter, it's just about adding some few headings to the later paragraphs in the intro. Otherwise the intro is as large as the rest of the article if not more. Said: Rursus (☻) 21:48, 15 December 2008 (UTC)

Whipped into shape?

Hi everyone. Recently I've just whipped up an article on a relatively unknown star into GA candidate status from scratch as a test of my abilities and found it fairly straight forward. Now I plan to do so with some more known stars and I chose Regulus first. Also, as I learned supposedly from what's already here, Regulus is known as one of the Royal stars from Ancient Persia (although 3000 BC might be wrong, see that section above for my comment).

Long story short, is there anyone interesting in collaboration on whipping Regulus up to a GA/FA, and perhaps Royal stars as well? Either reply here or message me on my talk page. SkarmCA (talk) 17:25, 18 December 2008 (UTC)

gravity darkening

Is gravity darkening the real reason that the equator is dimmer then the poles? becues i thought it was becuse the surface was farther away from the core of the star meaning it would be cooler.Confront (talk) 08:19, 4 March 2009 (UTC)

Gavity Darkening

see: http://ns.umich.edu/htdocs/releases/story.php?id=8374. Quote "The 90-year-old theory that predicts the extent of this "gravity darkening" phenomenon has major flaws, according to a new study led by University of Michigan astronomers....... "In some cases, we found a 5,000-degree Fahrenheit difference between what the theory predicts and what our actual measurements show," Monnier said. "That has a big effect on total luminosity. If we don't take this into account, we get the star's mass and age and total energy output wrong." —Preceding unsigned comment added by 82.161.142.131 (talk) 15:43, 19 April 2011 (UTC)

What is the shadow width?

67 miles (Occult Watcher says 66 (@ NYC)) is the width foreshortened along the Earth's surface. Per , and basic geometry, with spherical asteroid the "umbra" is 1.37km smaller than Erigone (72.7+/- something) and the penumbra is the same amount larger, so shadow width is not 73. Maybe there should be a clarification. Sagittarian Milky Way (talk) 02:48, 20 March 2014 (UTC)

Orbits

I removed the statement that Regulus BC would be thought to take several millions of years to orbit Regulus A. If the distance of 5000 AU is correct, a circular orbit would take something of the order of 5000^3/2*(M_Sun/M_{Regulus System})^1/2 y = 160 ky. And I guess the velocity isn't known with sufficient accuracy to determine the shape of a possible orbit. In any case, the statement is not backed up by the cited reference (for the catalogue entry, see ). Icek~enwiki (talk) 11:15, 11 September 2016 (UTC)

Rotational Velocity

The side bar gives the rotational velocity in terms of v sin i, but from interferometry and polarimetry [ref 26] we know the inclination (i) of this star and its actual rotational velocity, i.e. v without the sin i. — Preceding unsigned comment added by 129.94.163.79 (talk) 06:24, 9 October 2018 (UTC)

Spectroscopic binary vs binary star

The article is unclear as to whether there are four or five stars associated with Regulus. It lists Regulus A as being a spectroscopic binary with Regulus D and also as being a binary system with an unnamed(?) white dwarf. If both statements are accurate, then Regulus has five stars, not four as stated in the introduction and Stellar System sections. If the white dwarf has not yet been confirmed, then the Stellar System section needs to be rewritten to make it clear that the fifth star is hypothetical but presumed to exist based on the shape and rotational velocity of Regulus A. — Preceding unsigned comment added by Nick3193 (talk • contribs) 21:01, 16 September 2019 (UTC)

Where does it say that component D forms a spectroscopic binary with Regulus A? How could it, with that name? Lithopsian (talk) 15:28, 17 September 2019 (UTC)

Two weak vowel "u"s and never one followed by schwa (a)

I don't know what sort of strained speakers the OED in its heyday was listening to but almost every speaker of English in England at least would never be so cumbersome as to try and pronounce Reg-y(u)-las, as if to match in non-Rhotic English the words "Regulars" it certainly maintains the same 2nd and 3rd vowel in normal speech to avoid that and to be a more natural ending, as most words ending 'us' there is a very subtle but very important difference. This has always been taught in my schools and upbringing as enabling children to spell more easily as well, you don't turn all endings into straight schwa, the language is not quite that level of base. Not yet.- Adam37 Talk 12:11, 29 September 2019 (UTC)

Question

According to the article, Regulus is probably over a billion years old because it contains a white dwarf.

However, Sirius, which is thought to be around 240 million years old, also contains a white dwarf.

How is "Regulus is over a billion years old" deduced from this? Pancakes321 (talk) 11:03, 11 August 2025 (UTC)

Sirius B is from a more massive star than the Regulus white dwarf, hence reaches the white dwarf stage much more quickly. The two can't really be compared. Lithopsian (talk) 11:29, 11 August 2025 (UTC)

This is based on the estimated lifetime of the progenitor. 21 Andromedae (talk) 13:30, 11 August 2025 (UTC)

Something's wrong I can feel it

Regulus Aa's mass is slightly over 4 solar mass.

Their orbital period is about 40 days.

The semi major axis is... 6 solar radii? Pancakes321 (talk) 02:50, 18 September 2025 (UTC)

Well that is not actually the axis, but still the inclination is near 90° so there won't be a huge difference. I have edited the article for now with a different reference that gives an actual separation that corresponds closely to what is expected from Kepler's Third Law. To answer the apparent discrepancy between an axis of 6 R_☉ and a separation more like 75 R_☉, consider that the 6 R_☉ value is the projected semi-major axis of the primary. The projected semi-major axis of the secondary will be over ten times that value. Anyway, 6 R_☉ shouldn't be in the axis field in the starbox. I wonder how many other cases there are like this, perhaps less obvious? Lithopsian (talk) 15:25, 18 September 2025 (UTC)