Talk:Standard candle
 | This redirect does not require a rating on Wikipedia's content assessment scale. It is of interest to the following WikiProjects: | |||||||
| ||||||||
.jpg){kind=small}
 | The contents of the Standard candle page were merged into Cosmic distance ladder and it now redirects there. For the contribution history and old versions of the merged article please see its history. |
"Recently"
[edit]The section on "Eclipsing binaries" uses relative descriptions of time: "In the last decade ... Recently". This isn't a good idea, as it means the article ages badly. It would be much better (and more future-proof) if it gave approximate dates instead. -- Finlay McWalter | Talk 22:40, 15 December 2006 (UTC)
- How bout, "since the 1990s"? Sagittarian Milky Way 06:51, 25 March 2007 (UTC)
Population I/II Cepheids
[edit]I think that the last paragraph is incorrect; however, I am not an expert. My understanding is that:
- The Population II Cepheids, or W Virginis variables, have lower luminosity, than the Population I, or classical, Cepheid variables.
- The distances in the Milky Way had been measured using W Virginis variables (and RR Lyrae variables, also Population II stars).
- The extra-galactic distances had been measured using classical Cepheid variables.
- When W. Baade discovered the star populations, only the extra-galactic distances were affected. The distances in the Milky Way were not affected.
JTMnen 07:57, 28 August 2007 (UTC)
Measuring distances
[edit]In order to further developing this article, it may be a good idea to include an extensive section on measuring cosmic distances. I think this section should discuss each of the significant methods, along with their respective strengths and weaknesses (in terms of accuracy and range). Here is a candidate list:
- Trigonometric parallax
- Variables: Eclipsing binary, Cepheid variable, RR Lyrae variables, Novae
- Planetary nebula luminosity function
- Globular Clusters (via main sequence curve)
- Tip of the red giant branch
- VLBI: Radio jet proper motion
- VLBI: Maser proper motion
- Sunyaev-Zel'dovich effect
- Surface brightness fluctuation
- Tully-Fisher relation
- D-sigma relation (ellipticals)
- X-ray burster
- Brightest cluster galaxy
- Type Ia supernovae
- Gravitationally lensed quasars
- Gamma ray bursters
- Coalescing massive black holes
These can probably be sub-grouped by range. Is there anything else I need to include? Thanks.—RJH (talk) 16:50, 18 October 2008 (UTC)