User:CalRis25/Temp-Discussion-Misc

Some thoughts regarding "standards" astronomical articles for

General recommendations

• Which names of objects should be used (Bayer, Flamsteed, HD, BD etc.) inside articles? My recommendation:
  • Stars: if available use the Bayer-designation (e. g. alpha Delphini), otherwise use a designation in this order: Flamsteed (e. g. 15 Del), HD (e. g. HD196867). If none of these is available, use any other designation at your discretion.
  • Nebulae: Messier-number if available otherwise an NGC-number. If none of these is available, use any other designation at your discretion.
• Accuracy of values (how many decimal places?) for brightness. Should the value be rounded or simply truncated? My recommendation: no rounding and only 1 decimal place as the values in the different catalogues vary too much, e. g. 3.8, 12.3, -0.3
• Double/Multiple star systems: mag?
• Distances: light-years or parsec or both or depending on context?
• Which catalogues/sources should be used to get values for brightness, distance, size etc.?
  • HR (Harvard Revised HR, Bright Star Catalogue BSC): for stars brighter 6.5m (includes spectral type)
  • HIP (Hipparcos Catalogue) and TYC (Tycho Catalogue): precise positions
  • PPM (for stars not included in the HR/BSC): includes spectral type
  • Other catalogues as is deemed necessary

Example: alpha Delphini is listed by various as catalogues as follows: Simbad: m=3.771 as HR7906 (= Bright Star Catalogue): m=3.77 mit Sp=B9IV as HD196867: m=3.86 (photovisual magnitude) as HIP101958: m=3.77 (Johnson V System) as BD+15 4222: m=3.5 (estimated visual magnitude) as PPM138790: m=3.8 both HD and PPM claim that this star is B8 instead of B9 (the latter from XEphem) http://www.alcyone.de/SIT/ is a good starting point as it contains data for the bright stars (6.5m and brighter) from various catalogs (BSC/HR, a Variable Star Catalogue, SAO).

Recommendations concerning constellation

• Minimum information for stars mentioned in the "Notable Features"-section of the Constellation-articles. Should there be any minimum information? If yes which?
  • Spectral class: only e. g. O3 or O3-Ia?
  • Proper name if available: e. g. Betelgeuse, Rigel
  • Bayer-designation if available: e. g. alpha Delphini
  • Distance in light-years if near? If yes, what is "near"?
  • Should there be a minimum-magnitude for an object to be listed (in order to prevent listmania)?
• Values for RA and Dec.: giving here ONE specific value is rather ambiguous as long as it isn't clearly stated which "point in space" is meant. Solutions:
  • Indicate its extension "RA: 20h13 to 21h06", "Dec: +2.2° to +20.8°" (see constellation section of "E-Sky" http://www.glyphweb.com/esky/default.htm)
  • State RA/Dec for the principal star of the constellation, i. e. the Alpha-star (not necessarily the brightest star).
• "On meridian": giving the "exact" hour seems to me to be overdoing things. Giving a date would be more than enough for anybody to gauge if a constellation is "up" or not, wouldn't it?
• Order of "Bordering Constellations": start at the north and then continue clockwise