Argh, I read the list too fast...

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Arneb, Eroica - not even close.

You might need a telescope...

I thought that might be a hint, but apparently not!


Are you looking for one star, or two (the one with the faintest apparent magnitude and the one with the faintest absolute magnitude)?

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I'd ask you to consider how bright Alpha Canis Majoris B is...

In addition, I think we are looking for two stars.

And the possibility of a third companion

I have to protest here - The magnitude estimates of the Bayer-Flamsteed code are visual magnitudes, so that all double stars with visually inseparable components appear in their composite apparent magnitude. Sirius B contributes (very weakly) to apparent magnitude of Alpha canis majoris - Sirius. In the context of Bayer-Flamsteed, the existence of however many components of a visible star is irrelevant.

It's a cunning trick question, but I don't think it works (this time). In my opinion, it should be Eroica's turn.

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JOOC, when I looked over the constellations, five of them did not seem to have an alpha (including Sagittarius--whoops no not Sagittarius, some other), what's the story there?

hheb

The constellations without an alpha - two of them are Vela and Puppis. These have an alpha - just that it is alpha carinae (Canopus). The designation scheme applies to the whole of Argo Navis.

Arneb

It's a bit of a QI question, but hardly a trick question.

The faintest absolute magnitude alpha is two degrees from its partners, does not add to a combined magnitude and has always been known as a separate star.

The faintest visual magnitude alpha component is probably a little less clear cut, but an answer is quite clearly listed in the same sources that Eroica has been trawling (ie: Wikipedia).

The lack of an Alpha in Leo Minoris is said to be the result of a blunder by the 19th century English astronomer Francis Baily, who assigned Bayer letters to the LMi's stars, but forgot to label 46 LMi as Alpha! (Source: Astronomy (Eyewitness Companions) by Ian Ridpath.)

In Norma, the stars that Lacaille originally designated as Alpha and Beta have since been incorporated into Scorpius (N and H Sco respectively) - Ridpath again.

I agree. I had actually copped on that you were looking for a binary star before you started dropping hints.


Alpha-2 Librae - this has a visual magnitude of 5.2.

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Eroica

A good answer - the dimmest alpha visible to the naked eye! I hadn't thought of that one. Ten QI points.

To get at the answers I was thinking of, I'll drop some hints...


1) The faintest absolute magnitude for an alpha. Well it can't be far away, we'd never see it, especially around a bright star. It would help if it was two degrees away from the parents and an extremely dim star type.

I wasn't looking for the Alpha brown dwarf, that might be a load of bull anyway (it might not exist at all).

2) The faintest visual magnitude is a more sporting question. Again it would be dim and a member of a multiple star system. I am not looking for a spectroscopic component, nor am I interested in the truely obscure optical doubles.

I have found Alpha Draconis B which could be a good answer. The trouble is it hasn't be imaged so the companion (low mass white dwarf?) hasn't got a visual magnitude.

I was thinking of two trinary systems, one Spring one Summer. Neither are particularly dim and are visible to the whole planet. One of the stars is explicitly in the Wikipedia lists.

Proxima Centauri?

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With an absolute magnitude of 15.5, the red dwarf Alpha Centauri C is one of the dimmest stars in the sky. It was only discovered in 1915.

An interesting possibility for an even fainter "star" would be a brown dwarf. Alpha Tauri might have one (or not).

Eroica - any luck with the faintest visual magnitude? The ones I was thinking about are a couple of magnitudes fainter than Proxima.

Alpha Aurigae B?

It's called BD+45 1077B in SIMBAD

According to the Washington Double Star Catalog, it has a visual magnitude of 17.10.

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Capella is a difficult system. My understanding of B is the current interpretation Ab - ie: a yellow super giant, magnitude +0.96. The catalogs have used B through G to represent field stars - not bound to the Capella system.

However I'll take the answer to mean Capella D (or Hb). This is a red dwarf magnitude 13.7 which beats my answer of Alpha Leonis C (13.5) . Alpha Aurigae Hb is the faintest bound Alpha.

Eroica, your turn.

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Was it Karl Seyfert or Edwin Hubble. I'm just guessing. Or could it be Charles Meisser?

None of those, according to my source.

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Harlow Shapley?

How about Issac Newton?

Can you give us a year?

Correct!

My source was Burnham's Celestial Handbook (Volume 2, page 989).

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