Since we are getting quite some data about stars, it would be nice to be able to log10(), sin() and cos() in SPARQL. Specifically:

1. https://www.wikidata.org/wiki/Property:P7015 works with absolute values, which is fine for planets/asteroids, but for stars astronomers normally use decimal logarithm of the surface gravity. Thus in order to effectively filter stars in SPARQL it would be nice to have log10()
2. Normally in wikipedia articles about stars, there is a table with neighborhood stars (e.g. <10pc). Having RA and DEC for both star, one can calculate angular distance, and knowing distance from Earth to them, it is trivial to get distance between them. I can write SPARQL query for ListeriaBot, but I need trigonometry for that.

I can see that it is possible to write blazegraph custom functions bigdata operators: https://wiki.blazegraph.com/wiki/index.php/CustomFunction