Journals

• Nature
• Science
• NASA's ADS (also available here)
• arXiv: astro-ph: daily / weekly / search interface / uploads (UK mirror)
• ApJ
• MNRAS
• PASP
• A&A
• PASJ
• AJ
• ARA&A
• Saas-Fee Advanced Courses for Astrophysics and Astronomy
• Active Galaxies Newsletter
• Leicester University Library
• IoA (Cambridge) Library

Physical data

• NIST Physical Reference Data
• X-ray data booklet
• Verner's atomic data for astrophysics
• TOPbase Opacity Project database
• Zombeck (Handbook of Space Astronomy and Astrophysics)
• Photoelectric edge energies (from Verner et al. 1995)
• X-ray properties of the elements
• X-ray interactions with matter
• X-ray data server at Uppsala University (Sweden)
• Information on the elements from American Elements
• Energy unit converter
• Time conversion
• HyperPhysics notes
• HyperMaths notes
• Differentiation/Integration formulae

Observatories

• Chandra CXC (and UK mirror)
• XMM-Newton homepage
• RXTE GOF
• INTEGRAL
• Swift: at GSFC and in the UK
• Astro-E2: JAXA/ISAS, NASA/GSFC, ESA

• BeppoSAX
• ASCA GOF
• ROSAT
• EUVE
• Ginga
• EXOSAT

• Liverpool Robotic Telescope
• FUSE
• HST
• JWST - the next BIG space telescope
• Lick/UCO
• ESO
• ING
• AAO
• SAAO
• Gemini
• CTIO

• VLA
• MERLIN
• UKIRT
• JCMT
• Spitzer
• ALMA - Atacama Large Millimeter Array
• SKA - square kilometer array

• LISA - gravitational waves from space
• LIGO - ground based gravitational wave detector (US)
• GEO600 - ground based gravitational wave detector (Germany-UK)
• VIRGO ground based gravitational wave detector (France-Italy)
• AMANDA - neutrinos in Antarctica
• Super-Kamiokande neutrino observatory in Japan
• Sudbury Neutrino Observatory (Canada)

Astronomical databases

• XMM-Newton data archive
• Chandra data archive (and mirror site at LEDAS, Leicester)
• MAST Multi-Mission Archive at Space Telescope
• Beppo-SAX (NFI) data archive
• NED
• CDS/Simbad Strasbourg
• The SDSS
• Infra-red Processing and Analysis Center
• NSSDC: National Space Science Data Center
• Leicester's 'Digitized Sky Survey' Site
• SkyView Virtual Observatory
• HEASARC Archives
• LEDAS Archives
• ScanPI (IRAS survey data)

Notes

• Eric Weisstein's World of Science (physics, mathematics, astronomy)
• Hypermath
• Hyperphysics
• PlanetMath.org
• Encyclopedia of Astronomy and Astrophysics
• AstroWeb: Astronomy Resources
• An Astronomy Hypertextbook
• Wikipedia - the on-line encyclopedia
• "Handbook of Mathematical Functions" by Abramowitz & Stegun (1964)

Statistics

• The California-Harvard Astrostatistics Collaboration
• Practical Statistics for Astronomers by J. V. Wall & C. R. Jenkins
• Electronic Statistics Textbook
• Some notes on goodness of fit tests
• Statistics quotes
• Statistical Consulting Center for Astronomy
• Bayesian Inference for the Physical Sciences by Tom Loredo
• A Statistics Bibliography
• StatCodes
• MCMC Tutorial
• MCMC Preprint Service
• e-Handbook of Statistical Methods
• Statistics lectures: Part I and Part II by Peter Freeman (from X-ray Astronomy School 2003).
• The Royal Statistical Society
• The Understanding Uncertainty project

Astronomical software

• The XMM SAS (see also the "SAS Cookbook" from MPE and "ABC Guide" from GSFC)
• The Chandra CIAO software
• Starlink
• Statistical codes (at PSU)
• Numerical Recipes
• R: home; manuals; FAQ; CRAN
• IRAF Homepage
• PG Plot
• XANADU (ie: XSPEC, XRONOS, XIMAGE)
• FTOOLS
• SAOimage DS9
• QDP
• StatLib at CMU
• Numerical methods
• Bevington & Robinson codes ("Data Reduction and Error Analysis for the Physical Sciences")
• Cloudy - photoionised plasma by Gary J. Ferland
• XSTAR - photoionised plasma by Tim Kallman
• Free software for Atomic and Plasma Physics

Programming

• Bash reference manual
• Bash scripting guide
• Bash "how to..." guide
• Introduction to Bash

• NAG for Fortran 90
• Fortran 90 articles (Michael Metcalf)
• Fortran 90 for the F77 programmer
• Fortran library
• Notes on Fortran

• IDL homepage (ITT, formerly RSI)
• IDL Astronomy library (at GSFC)
• IDL codes (Craig Markwardt)
• IDL Astronomy library (at Tubingen)
• Coyote's Guide to IDL Programming (by David W. Fanning)
• Manipulate and Visualize Scientific Data - An online IDL tutorial
• Johns Hopkins Applied Physics Lab IDL Web Page
• Introduction to IDL from astronomers
• IDL online documentation

• R project homepage
• Download R for Linux/Mac OS/Windows
• R documents (main page)
• books about R
• R tutorial (2006, Summer School for Astronomers, Penn State)
• A Quick, Painless Tutorial and Reference on the R Statistical Package (Prof Norm Matloff)
• SimpleR (John Verzani, 2002)
• R reference card
• R by example (Ajay Shah)
• R graphics gallery
• Using R (John Maindonald)

• Beginners Guide to HTML (NCSA)
• W³C HTML homepage
• W³C MarkUp Validation Service
• IconBazaar - graphics icons
• Icon Archive - graphics icons
• Composing good HTML
• Bare Bones guide to HTML
• HTML quick reference
• HTML tutorial

• Download Tcl/Tk
• Tcl tutorial
• Tcl/Tk manual pages
• Tcl commands

• Tutorial and Cookbook (Adobe Systems Inc)
• First Guide to PostScript
• Postscript tutorial (basic)
• Practical PostScript (by David Byram-Wigfield)

• awk
• LaTeX
• Help with LaTeX commands
• LaTeX project homepage
• GhostScript/View
• Grace
• Emacs

• AAAS (American Association for the Advancement of Science)
• AAS (American Astronomical Society)
• HEAD (High Energy Astrophysics Division)
• The Royal Society (RS)
• The Royal Astronomical Society (RAS)
• Institute of Physics
• Science & Technology Research Council (STFC) - formerly PPARC

News

• GCN - The Gamma ray bursts Coordinates Network
• ATel - The Astronomer's Telegram
• ASM Light Curves from RXTE
• Swift/BAT Hard X-ray Transient Monitor

• Financial Times
• Independent
• Guardian
• Telegraph

• Scientific American
• New Scientist
• Wired
• Sky and Telescope
• The Economist

• The AstroStat Slog Weaving together Astronomy + Statistics + ...
• Statistical modeling, causal inference, and social science (Andrew Gelman)
• Cosmic Variance (group effort)
• Mind Hacks
• Bad Science
• Jerry Coyne (et al.) evolution blog
• Understanding Uncertainty blog (David Spiegelhalter)
• Cognition and Culture by Dan Sperber.
• Not Exactly Rocket Science by Ed Yong
• Richard Wiseman's blog.
• Jason Rosenhouse Math's & stuff
• Retraction Watch
• R bloggers
• CrossValidates for statos
• StackOverflow for coders

• In Our Time (Radio 4)
• Philosophy Bites with David Edmonds and Nigel Warburton

Debunk

• Not even wrong!
• The Skeptics Society
• Skeptic Magazine
• Skeptic Report
• Talk Origins
• Behind the Headlines (NHS) disect the media's inability to cover medical news properly
• Stats experts disect the news
• Help with statistics
• Ben Goldacre's Bad Science column. See also www.badscience.net
• The Skeptic's Dictionary