Miscellaneous

Useful tools, information for observers:

	Astronomical instrumentation directory (epoch ~ 2004), Telescope collecting area vs date, MOS projects (epoch ~ 2011)
	Constellation map
	SIGNAL exposure-time calculator, Fortran code
	Sky brightness (introductory page), La Palma technical note 115 (full report), Sky-brightness calculator
	Slit-vignetting as a function of wavelength (Fortran code)

Other astronomy-related:

	Astronomy on the QM2
	Best-title awards - nominations welcome
	Email directory history / statistics The email directory itself is no longer maintained. A copy of the October 1999 edition can be obtained from crb@ing.iac.es
	Mercator construction
	RGO summer students 1956-87
	Scientific impact of large telescopes, Benn and Sanchez (2001), PASP, 113, 385

Other:

	4-dimensional crossword, other crosswords
	Karpov vs Benn
	Nature notes
	Optical illusions