# Star distances **URL:** \ **Category:** Factual Questions\ **Created:** [February 2, 2014, 12:01am UTC](https://boards.straightdope.com/t/star-distances/680322 "2014-02-02T00:01:59Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [February 2, 2014, 6:49am UTC](https://boards.straightdope.com/t/star-distances/680322/21 "2014-02-02T06:49:13Z")
> [@cmyk](#): > > It would violate direct observation with optics alone. > > If they were that close—hell, if they were even just outside the boundary of our solar system—we’d be able to resolve a disc under magnification (perhaps even with the naked eye for some red giants). Alas, under the strongest magnification, they still only resolve as points. Interestingly, we’ve successfully resolved [Betelgeuse](http://en.wikipedia.org/wiki/Betelgeuse#Imaging_breakthroughs) as a disk. > [@wedgehed](#): > > Does this mean that we have no way of measuring the distance of the farther background stars? Not as accurately, but there _are_ other methods. Such as redshift - the farther away an object, the greater the redshift. And there’s several [other](http://en.wikipedia.org/wiki/Cosmic_distance_ladder) methods, like using particular types of stars as “standard candles” that have a predictable brightness at a given distance. ---
**Author:** ![TimeWinder](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@TimeWinder](https://boards.straightdope.com/u/TimeWinder)\ **Post date:** [February 2, 2014, 8:48am UTC](https://boards.straightdope.com/t/star-distances/680322/22 "2014-02-02T08:48:43Z")
We’ve also actually checked. We’ve had several probes further out (in some cases much, much further out) than the OP’s conjectured distance take pictures back toward Earth. No stars showed up that weren’t supposed to be there, nor did the probes pass by any they felt like photographing, reporting, or adjusting course to account for the gravity of. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [February 2, 2014, 11:52am UTC](https://boards.straightdope.com/t/star-distances/680322/23 "2014-02-02T11:52:50Z")
> [@Great\_Antibob](#): > > They can’t be that close without violating what we know about physics. This. All knowledge is contextual. You can’t change a fact of nature without changing a lot of other things. The distances to the stars rely on quite a few other facts we know about the universe, and those facts are related to quite a few other facts. If you think stars are that close, you’ve got to back up that claim with some very fundamental physics. ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [February 2, 2014, 12:06pm UTC](https://boards.straightdope.com/t/star-distances/680322/24 "2014-02-02T12:06:41Z")
I understand how astronomers find out how far away the stars are, and how big and how bright, and even how old they are, but how do they find out their names? ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [February 2, 2014, 1:01pm UTC](https://boards.straightdope.com/t/star-distances/680322/25 "2014-02-02T13:01:56Z")
> [@wedgehed](#): > > Does this mean that we have no way of measuring the distance of the farther background stars? Stellar distances are typically estimated by evaluating luminosity and spectral content (the characterisic distribution of wavelenghts of visible, infrared, and ultraviolet light from a star) which determines the composition and stage of life of a star. By knowing what the brigtness of a star should be at some reference distance, astronomers can estimate the distance (and by measuring the frequency shift, the radial speed) of a star with respect to an Earth reference frame. At farther (galactic and beyond) distances, objects such as Cepheid variables which are of known luminosity (referred to as “standard candles” in astronomy jargon) are used as to estimate distances and speeds, as well as the metric expansion of space as indicated by the “red shift” observed by Slipher, Keeler, and Campbell and calculated by Hubble and Humeson. > [@Bill\_Door](#): > > I understand how astronomers find out how far away the stars are, and how big and how bright, and even how old they are, but how do they find out their names? Formerly, they called Information. Now they just look them up on Facebook. Stranger ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [February 2, 2014, 1:32pm UTC](https://boards.straightdope.com/t/star-distances/680322/26 "2014-02-02T13:32:26Z")
One way that might work is if the solar system were inside something similar to a black hole, our sun might be a a reversed time image of it’s former self and time in our ‘bubble’ runs backwards, that ‘bubble of space’ could have it’s own laws of physics including the speed of light, and there is a limit as to how far light could travel, this we observe as the expansion of the universe. But this would only bring stars to the distance of just outside the solar system, not close to the moon. But with the speed limit lifted and new laws of physics in play the stars may be easier to get to. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [February 2, 2014, 2:44pm UTC](https://boards.straightdope.com/t/star-distances/680322/27 "2014-02-02T14:44:54Z")
> [@Stranger\_On\_A\_Train](#): > > Formerly, they called Information. Now they just look them up on Facebook. > > Stranger Are you sure about that? I thought they were named by the [International Star Registry](http://starregistry.com/). 😉 ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [February 2, 2014, 6:22pm UTC](https://boards.straightdope.com/t/star-distances/680322/28 "2014-02-02T18:22:31Z")
Interestingly enough, in the early days of astronomy there was a legitimate debate over star distances due to an apparent conflict between star brightness and parallax. Copernicus had explained the lack of noticeable parallax by saying the stars were extremely far away. But to the naked eye and early telescopes, the stars appeared to have a small but discernible angular size due to an optical illusion. If they were as far away as Copernicus claimed, they’d have to be gigantic- as big as our entire solar system. This led for awhile to the Tychonic system, which was a compromise between the Ptolemaic and Copernican systems. [Previous page](https://boards.straightdope.com/t/star-distances/680322.md?page=1)