New post

SN8 3D Star Database: add Gaia Statistical DR2 positions for much enriched 3D view of our stellar neighborhood...benefits SN8 Stars, Double Stars, Clusters: video of GaiaSky DR2 bayesian distances dataset

[Key Point]: Using all or portions of the largest Gaia data processed for positions via specific statistical methods based on DR2 (& later DR3) offers a way to address a bunch of prior feature requests listed & linked below.

Example use of the Gaia data: ALBIREO IS NOT A BINARY STAR (link)

Below is a link to a 1080p HD video that shows the Epsilon Lyra region first in Gaia Sky (link)  using the Bailer-Jones et al bayesian distances dataset (link) then in SNpp8 & also a screenshot of a Gaia Sky star in Globular NGC 5272 (M3):

note:in one video I limited star draw distance since there are so many stars in Gaia DR2 bayesian distances dataset.

Bias in Bailer-Jones et al calculations has been further critiqued for a specific criteria subset of stars for which specific methods enable better distance estimation...released by the authors of the 2019 paper linked below::

"Distances for the Gaia RV set with corrected parallaxes"

see also these papers regarding bayesian distances & dataset bias:

   Opportunity for significant & useful improvement in Starry Night 3D Stars database with specific analysis of Gaia data & ideally also with the best of historical visual multiple stars orbital data in data sets such as USNO Sixth Catalog of Orbits of Visual Binary Stars

One very nice result will be improvement of modeling of nearby clusters & multiple stars regions that are able to be split visually by 'small' scopes (e.g. observing list "SAC - Best Multiple Stars" which I understand is the current focus in Starry Night) in amateur scopes in SN8 and other Star database(s) related topics & opportunity for Starry Night to continue to fill the software void in this domain:

      The Gaia DR2 paper indicates a very good match with WDSC down to 2 arc seconds of separation which covers many of the great multiple stars accessible to 'small' scopes...see page 4:

Gaia DR2 and the Washington Double Star Catalog:A Tale of Two Databases (link)

  • "Gaia DR2 is a game changer for double star astronomy....DR2 gives us solid information to help us plan and direct our research...only 33% of the 139,781 WDS records extracted from DR2 show definite signs of physicality while a solid factor (8%) do not, with a further 49% of unknown status due to a lack of good data
  • ..The Excel spreadsheet is large (38 MB...the database should be consulted to see if the selected star is physical or not"

In this forum over time there has been periodic interest expressed in SN:

1)      more accurately plotting angular separation over time (e.g. people can observe changes in separation is several top doubles over a lifetime...simulating that accurately in SN would be interesting & helpful).

2)      having a database/tool even better than Stellarium Astronomical calculator WUT Bright Double Stars (link) for finding & sorting double stars by separation & magnitude & transit time, etc.

3)      replacing the "Generic Tennis ball Binary Star Model" with orbits models (with plottable orbit lines ;-) for systems with reasonably well predicted orbits in the ORB6 (link) (click on the blue "P" at the right side of each entry to view plots) and OARMAC (link) catalogs of visual double ephemerides and

4)      for systems without good orbital data, plotting the individual stars of the multiple system in the current SN OBAFGKM stellar color textures (link)  & at 3D positions more accurately (= an improvement over the current 'generic 3D binary' tennis ball model). using Gaia DR2 positions (link)...

5) enhanced proper motion data e.g changes in constellations/asterisms, etc over time.

6) toggle switches for Star databases e.g. just plot USNO, or Gaia 3D, or just plot Double Stars, or just plot stars with exoplanets, etc.

example SN requests that can be addressed (links) 

example SS dev & requests links:



7)    Acknowledgement: the 11 current 'non-visual' close/'contact' type 3D binary models in 'favorites'  the "Growing database of Bradstreet/Spitz 3D binaries (link) only included with Starry Night provide accurate models of specific binary systems" is a nice educational addition.  A few models of visual binaries with the best ORB6 data would be a wonderful addition with Gaia 3D refined DR2+ statistical positions for the rest.

Thanks! Chadwick


Please sign in to leave a comment.