Miscellaneous

Questions that really don't belong in any category, even a new one...

Scales:

• What are the masses and radii of the following objects: electron, proton, earth, sun, solar system, globular cluster, open cluster, galaxy cluster.

• What is the spatial extent of the visible universe?

• What is the angular extent of Virgo?

• How big is a typical globular cluster on the sky?

• What do you know about planetary nebulae? What is their extent?

Coordinates:

• What is the mean local sidereal time at midnight on March 20th? (RS)
• What is the RA of the sun at the autumnal equinox? (RS)

Brightest objects in the sky:

• What is the brightest object in the night sky? Second? Third? (RS)
• What is the brightest star? (RS)

Other:

• If we go out at a clear night, how many stars can we see with naked eyes?

• What is Vega, Sirius?

• What is the Cygnus loop, Crab nebula? What are their angular extents?

• How would you define "strong gravity"?

• How are muons created in the atmosphere?
  • What are cosmic rays? What type of particle?

Astrophysics