Talk:Geminga
Add topicLatest comment: 1 year ago by SevenSpheres in topic Age
 | This article is rated Start-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects: | |||||||||||||
| ||||||||||||||
.jpg){kind=small}
Identification with a visual source for parallax and distance - any update from Gaia
[edit]- The proper motion and distance was derived ~2007 from the visual? images taken with the WFC of ACS on HST (of the "faint blue object" found by the Einstein observatory? ). (Was no parallax reported from Hipparcos for it ? - too faint)
- What magnitude is the visual component (since it and colour affects Gaia accuracy) ?
- Has Gaia since 2013 provided a more accurate parallax (and distance) for Geminga ? - Rod57 (talk) 11:20, 4 November 2021 (UTC)
- As far as I can see from Gaia archive search, Geminga (in EDR3) has a position, and magnitude (20.620018) and bp_rp ? magnitude (0.8857765) but no parallax or radial velocity. Presumably it's too faint for Gaia. ... Gaia goals were parallax precision "200 μas at 20 mag", so Geminga could be at the limit. - Rod57 (talk) 14:34, 4 November 2021 (UTC)
Where does apparent magnitude come from
[edit]Infobox says apparent magnitude 25.5 and refs SIMBAD. I can't see it there. Is it in SIMBAD ? (Gaia EDR3 seems to say mag 20.6) And the Age ? - Rod57 (talk) 14:43, 4 November 2021 (UTC)
Age
[edit]The text says that Geminga is the remnant of a supernova that occurred 300,000 years ago, citing daviddarling.info. The infobox has a more precise age of 342,000 years, with no source. However, SIMBAD lists the designation SN 437, implying that the supernova was much more recent (occurring in the year 437). What is the actual age of Geminga? Where does "SN 437" come from? SevenSpheres (talk) 16:22, 3 May 2025 (UTC)
- Mignani 2011 lists a log(age) of 5.53, corresponding to an age of about 339,000 years. I've replaced the infobox value with that. Doesn't explain "SN 437". SevenSpheres (talk) 16:46, 3 May 2025 (UTC)