Free Astronomy Books

This is the updated list of astronomy books available for free download or online reading. These books and papers cover all the areas of astrophysics, cosmology, galactic and extragalactic astronomy, solar and stellar physics, celestial mechanics, planetary science, astrobiology, as well as some popular works. The books are made available free of charge to the reader by their authors or publishers. Here is a categorized directory of astronomy books. This page is updated daily.

1. An Introduction to Astronomy
   Forest Ray Moulton | The MacMillan Company, Published in 1916, 577 pages
2. Primordial Magnetogenesis
   Alejandra Kandus, Kerstin E. Kunze, Christos G. Tsagas | arXiv, Published in 2011, 107 pages
3. Gravitational Wave Detection by Interferometry
   Matthew Pitkin, Stuart Reid, Sheila Rowan, Jim Hough | arXiv, Published in 2011, 80 pages
4. Are We Alone?
   Gregg Easterbrook | The Atlantic Monthly, Published in 1988
5. Particle Physics Aspects of Modern Cosmology
   Robert H. Brandenberger | arXiv, Published in 1997, 70 pages
6. The Practical Astronomer
   Thomas Dick | Seeley, Burnside, and Seeley, Published in 1845, 588 pages
7. Protostars and Planets
   | Rice University, Published in 2015, 422 pages
8. Atlas of Peculiar Galaxies
   Halton C. Arp | California Institute of Technology, Published in 1966, 190 pages
9. Neutrinos and the Stars
   Georg Raffelt | arXiv, Published in 2012, 83 pages
10. Notes on Stellar Astrophysics
    James N. Pierce | Minnesota State University, Published in 2013, 299 pages
11. Advanced Topics in Cosmology: A Pedagogical Introduction
    T. Padmanabhan | arXiv, Published in 2006, 40 pages
12. Lopsided Spiral Galaxies
    Chanda J. Jog, Francoise Combes | arXiv, Published in 2008, 75 pages
13. Dense Matter in Compact Stars
    Andreas Schmitt | arXiv, Published in 2010, 146 pages
14. Observatories in Space
    Catherine Turon | arXiv, Published in 2011, 50 pages
15. The Beginning and the End: The Meaning of Life in a Cosmological Perspective
    Clement Vidal | arXiv, Published in 2013, 356 pages
16. An Exposition on Inflationary Cosmology
    Scott Watson | arXiv, Published in 2000, 93 pages
17. Protoplanetary Disks and Their Evolution
    Jonathan P. Williams, Lucas A. Cieza | arXiv, Published in 2011, 65 pages
18. Sky Surveys
    S. G. Djorgovski, A.A. Mahabal, A.J. Drake, M.J. Graham, C. Donalek | arXiv, Published in 2012, 62 pages
19. Dark Energy: Observational Evidence and Theoretical Models
    B. Novosyadlyj, V. Pelykh, Yu. Shtanov, A. Zhuk | Akademperiodyka, Published in 2013, 380 pages
20. Encyclopedia of Astrophysics
    Søren Bertil F. Dorch | Scholarpedia, Published in 2009
21. Celestial Navigation, Elementary Astronomy, Piloting
    Arturo Chiesa, Raffaele Chiesa | Sky and Sea Software, Published in 2010
22. Astronomy
    Andrew Fraknoi, David Morrison, Sidney C. Wolff | Unglue.it, Published in 2016, 1200 pages
23. TASI Lectures: Introduction to Cosmology
    Mark Trodden, Sean M. Carroll | arXiv, Published in 2004, 82 pages
24. The Geology of the Terrestrial Planets
    Michael H. Carr | NASA, Published in 1984, 322 pages
25. A Briefer History of Time: From the Big Bang to the Big Mac
    Eric Schulman | St. Martin's Press, Published in 2004, 207 pages
26. Consolidated Lunar Atlas
    Gerald P. Kuiper, et al. | Lunar and Planetary Institute, Published in 1960
27. Inflationary Cosmology and Structure Formation
    J. A. Peacock | arXiv, Published in 1996, 77 pages
28. A Guide To The Constellations
    Samuel G. Barton | McGraw-Hill, Published in 1928, 96 pages
29. The Fine-Tuning of the Universe for Intelligent Life
    Luke A. Barnes | arXiv, Published in 2011, 76 pages
30. Voyage to Jupiter
    David Morrison, Jane Samz | NASA, Published in 1980, 218 pages
31. Gravitational Wave Experiments and Early Universe Cosmology
    Michele Maggiore | arXiv, Published in 2000, 100 pages
32. Trans-Neptunian Objects: An Overview
    | Wikipedia, Published in 2014
33. The Hubble Constant
    Neal Jackson | arXiv, Published in 2014, 48 pages
34. Observations of the High Redshift Universe
    Richard S. Ellis | arXiv, Published in 2007, 115 pages
35. Great Astronomers
    Robert S. Ball | Isbister, Published in 1895, 392 pages
36. Mysteries of the Sun
    Ginger Butcher | NASA, Published in 2011, 20 pages
37. Planetary Theory
    Ernest Brown, Clarence Shook | Cambridge University Press, Published in 1933, 323 pages
38. Mars Science Laboratory
    | Wikipedia, Published in 2014
39. Textbook on Practical Astronomy
    George Leonard Hosmer | Wiley, Published in 1910, 252 pages
40. Introduction to Physical Astronomy
    Kenneth R. Koehler | University of Cincinnati, Published in 2010
41. Observational Probes of Cosmic Acceleration
    David H. Weinberg, et al. | arXiv, Published in 2012, 253 pages
42. The First Stars
    Simon C. O. Glover | arXiv, Published in 2012, 72 pages
43. The Formation and Evolution of the Solar System
    James Schombert | University of Oregon, Published in 2007
44. Spherical Astronomy
    F. Brünnow | Van Nostrand, Published in 1865, 559 pages
45. An introductory treatise on the lunar theory
    Ernest W Brown | Cambridge University Press, Published in 1896, 312 pages
46. Everything You Always Wanted To Know About The Cosmological Constant Problem
    Jerome Martin | arXiv, Published in 2012, 89 pages
47. Searching for Life Across Space and Time
    | The National Academies Press, Published in 2017, 133 pages
48. Lunar Stratigraphy and Sedimentology
    John Lindsay | Elsevier, Published in 1976, 311 pages
49. Cosmic Structure, Averaging and Dark Energy
    David L. Wiltshire | arXiv, Published in 2013, 55 pages
50. Short History of Astronomy
    Arthur Berry | John Murray, Published in 1898, 439 pages
51. Voyager 1 Encounters Saturn
    | NASA, Published in 1980, 51 pages
52. Mercury
    F. Vilas, C. Chapman, M. Matthews | University of Arizona Press, Published in 1989, 794 pages
53. Cosmology: Mankind's Grand Investigation
    Greg Bothun | Harcourt Brace College Publishers, Published in 1999, 129 pages
54. Curiosities of the Sky
    Garrett Putman Serviss | Harper & Brothers, Published in 1909, 300 pages
55. Elements of Astrophysics
    Nick Kaiser | University of Hawaii, Published in 2002, 435 pages
56. Introductory Lectures on Quantum Cosmology
    J. J. Halliwell | arXiv, Published in 1990, 107 pages
57. Celestial Mechanics: Notes and Work
    J.D. Mireles James | Rutgers University, Published in 2007, 128 pages
58. An Introduction into the Theory of Cosmological Structure Formation
    Christian Knobel | arXiv, Published in 2012, 102 pages
59. Ekpyrotic and Cyclic Cosmology
    Jean-Luc Lehners | arXiv, Published in 2009, 79 pages
60. To See the Unseen: A History of Planetary Radar Astronomy
    Andrew J. Butrica | NASA History Division, Published in 1996, 301 pages
61. Voyager 1 and 2: Atlas of Six Saturnian Satellites
    Raymond M. Batson | NASA, Published in 1984, 175 pages
62. Introduction to Dark Matter Experiments
    R. W. Schnee | arXiv.org, Published in 2011, 64 pages
63. String Cosmology
    James M. Cline | arXiv, Published in 2007, 47 pages
64. Man's Place in the Universe
    Alfred R. Wallace | Chapman and Hall, Published in 1904, 330 pages
65. Lecture Notes on High Energy Cosmic Rays
    M. Kachelriess | arXiv.org, Published in 2008, 82 pages
66. Exoplanet Observing for Amateurs
    Bruce L. Gary | Reductionist Publications, Published in 2007, 170 pages
67. Traces of Catastrophe
    Bevan M French | Lunar and Planetary Institute, Published in 1998, 120 pages
68. A Simple Guide to Backyard Astronomy
    Carol Beigel | , Published in 2008, 61 pages
69. High Performance Computing and Numerical Modelling
    Volker Springel | arXiv, Published in 2014, 108 pages
70. An Introduction to Cosmic Rays and Gamma-Ray Bursts
    A. De Rujula | arXiv, Published in 2007, 37 pages
71. The Beginning and Evolution of the Universe
    Bharat Ratra, Michael S. Vogeley | arXiv, Published in 2008, 69 pages
72. Lecture notes on the formation and early evolution of planetary systems
    Philip J. Armitage | arXiv, Published in 2010, 63 pages
73. Black-Hole Phenomenology
    Neven Bilic | arXiv, Published in 2006, 58 pages
74. Mathematical Problems Of Radiative Equilibrium
    Eberhard Hopf | Cambridge University Press, Published in 1934, 123 pages
75. Inflation and String Theory
    Daniel Baumann, Liam McAllister | arXiv, Published in 2014, 349 pages
76. Hours With A Three-Inch Telescope
    William Noble | Longmans, Green & Co., Published in 1887, 159 pages
77. Lectures on Inflation and Cosmological Perturbations
    David Langlois | arXiv, Published in 2010, 56 pages
78. A practical guide to Basic Statistical Techniques for Data Analysis in Cosmology
    Licia Verde | arXiv, Published in 2008, 52 pages
79. Chondrules and their Origins
    Elbert A. King | The Lunar and Planetary Institute, Published in 1983, 377 pages
80. Stellar Atmospheres
    J. B. Tatum | , Published in 2006
81. A Text-book of Astronomy
    George C. Comstock | D. Appleton and company, Published in 1901, 391 pages
82. General Astronomy
    | Wikibooks, Published in 2009
83. Photographs of Nebulae and Clusters
    James Edward Keeler | University of California Publications, Published in 1908
84. Introduction to relativistic astrophysics and cosmology through Maple
    V. L. Kalashnikov | arXiv, Published in 2001, 124 pages
85. The Complete Idiot's Guide to The Sun
    Jay M. Pasachoff | Alpha, Published in 2003, 350 pages
86. Galaxies and the Expanding Universe
    James Schombert | University of Oregon, Published in 2008
87. High Energy Astrophysics
    Jonathan Katz | The Benjamin/Cummings Publishing, Published in 1986, 338 pages
88. The Solar Magnetic Field
    Sami Solanki, Bernd Inhester, Manfred Schussler | arXiv, Published in 2010, 83 pages
89. Applied Cosmography: A Pedagogical Review
    Yu. L. Bolotin, et al. | arXiv.org, Published in 2018, 66 pages
90. Oulu Space Physics Textbook
    Reijo Rasinkangas | University of Oulu, Published in 2008
91. Practical Astronomy
    P. S. Michie, F. S. Harlow | John Wiley & Sons, Published in 1893, 246 pages
92. Stellar Superfluids
    Dany Page, et al. | arXiv, Published in 2013, 88 pages
93. Recreations in Astronomy
    Henry White Warren | Project Gutenberg,
94. The Shape of the Universe
    Gerd Pommerenke | viXra, Published in 2013, 321 pages
95. Advances in Modern Cosmology
    Adnan Ghribi | InTech, Published in 2011, 198 pages
96. Recent Developments in Gravitational Collapse and Spacetime Singularities
    Pankaj S. Joshi, Daniele Malafarina | arXiv, Published in 2012, 89 pages
97. Particle Physics and Inflationary Cosmology
    Andrei Linde | arXiv, Published in 2005, 270 pages
98. Gamma-Ray Bursts
    | Wikipedia, Published in 2014
99. Black Holes
    P.K. Townsend | arXiv, Published in 1997, 145 pages
100. Elementary Mathematical Astronomy
     C. Barlow, G. Bryan | University Correspondence College Press, Published in 1893, 442 pages
101. Cosmic Journey: A History of Scientific Cosmology
     N. S. Hetherington, W. P. McCray | American Institute of Physics, Published in 2009
102. Radiative Gas Dynamics
     David Weinberg | Ohio State University, Published in 2007
103. Introduction to Cosmology
     A. D. Dolgov | arXiv, Published in 2009, 58 pages
104. Archaeology, Anthropology, and Interstellar Communication
     Douglas A. Vakoch | NASA, Published in 2014, 330 pages
105. First Light
     Abraham Loeb | arXiv, Published in 2006, 157 pages
106. A New Astronomy
     David Peck Todd | American Book Company, Published in 1906, 437 pages
107. Lunar Orbiter Photographic Atlas of the Moon
     D.E. Hughes, J.K. Bowker | Lunar and Planetary Institute, Published in 1971
108. Supernova Remnants: The X-ray Perspective
     Jacco Vink | arXiv, Published in 2011, 78 pages
109. Radiative Processes in High Energy Astrophysics
     Gabriele Ghisellini | arXiv, Published in 2012, 157 pages
110. Massive Stars and their Supernovae
     F. Thielemann, R. Hirschi, M. Liebendorfer, R. Diehl | arXiv, Published in 2010, 81 pages
111. Resources of Near-Earth Space
     J. S. Lewis, M. S. Matthews | University of Arizona Press, Published in 1993, 977 pages
112. Cosmic Rays and the Search for a Lorentz Invariance Violation
     Wolfgang Bietenholz | arXiv, Published in 2008, 81 pages
113. Chemistry in Protoplanetary Disks
     Thomas Henning, Dmitry Semenov | arXiv, Published in 2013, 84 pages
114. The Astronomy of the Bible
     E. Walter Maunder | Richard Clay & Sons, Published in 1908
115. Multi-messenger Astronomy and Dark Matter
     Las Bergstrom | arXiv, Published in 2012, 105 pages
116. Introduction to Millimeter/Sub-Millimeter Astronomy
     T. L. Wilson | arXiv, Published in 2009, 106 pages
117. Hubble 25: A Quarter-Century of Discovery with the Hubble Space Telescope
     Dylan Steele (ed.) | NASA, Published in 2015, 78 pages
118. Cosmology
     V. A. Rubakov | arXiv.org, Published in 2018, 56 pages
119. Observing the Sky from 30S
     Roberto Mura | Wikibooks, Published in 2010, 86 pages
120. Cosmic Microwave Background Anisotropies up to Second Order
     Nicola Bartolo, Sabino Matarrese, Antonio Riotto | arXiv, Published in 2007, 53 pages
121. Practical Astronomy for Engineers
     Frederick Hanley Seares | Stephens, Published in 1909, 160 pages
122. An Introduction to Quantum Cosmology
     D.L. Wiltshire | arXiv, Published in 2003, 60 pages
123. Ultrahigh Energy Cosmic Rays: Facts, Myths, and Legends
     Luis Alfredo Anchordoqui | arXiv, Published in 2011, 92 pages
124. Galaxy systems in the optical and infrared
     A. Biviano | arXiv, Published in 2008, 60 pages
125. The Elements of Theoretical and Descriptive Astronomy
     Charles J. White | J. Wiley, Published in 1909, 322 pages
126. Gravitational Waves: Sources, Detectors and Searches
     Keith Riles | arXiv, Published in 2012, 79 pages
127. A Practical Introduction to Numerical Hydrodynamics
     Garrelt Mellema | Leiden University, Published in 2003, 124 pages
128. Supernovae
     | Wikipedia, Published in 2014
129. Dwarf-Galaxy Cosmology
     Regina Schulte-Ladbeck, at al. | Hindawi Publishing, Published in 2010, 238 pages
130. Elementary Astronomy
     James N. Pierce | , Published in 2013, 134 pages
131. Magnetic Fields, Strings and Cosmology
     Massimo Giovannini | arXiv, Published in 2006, 76 pages
132. The Search for Extraterrestrial Intelligence, SETI
     Philip Morrison, John Billingham, John Wolfe | NASA, Published in 1979, 293 pages
133. Astronomy of To-day
     Cecil Goodrich Julius Dolmage | Seeley and co., Published in 1910
134. Primordial Nucleosynthesis: from precision cosmology to fundamental physics
     F. Iocco, G. Mangano, G. Miele, O. Pisanti, P.D. Serpico | arXiv, Published in 2009, 148 pages
135. From Chaos to Consciousness: A Brief History of the Universe
     Mike Corwin | Bookboon, Published in 2015, 166 pages
136. To a Rocky Moon: A Geologist's History of Lunar Exploration
     Don E. Wilhelms | University of Arizona Press, Published in 1993, 524 pages
137. Pioneers of Science
     Oliver Lodge | Macmillan and co, Published in 1905, 421 pages
138. Primer Of Celestial Navigation
     John Favill | Cornell Maritime Press, Published in 1944, 300 pages
139. Quantization in Astrophysics, Brownian Motion, and Supersymmetry
     F. Smarandache, V. Christianto | MathTiger, Published in 2007, 516 pages
140. The Galactic Habitable Zone I. Galactic Chemical Evolution
     G. Gonzalez, D. Brownlee, P. Ward | arXiv, Published in 2001, 57 pages
141. Modified Gravity and Cosmology
     T. Clifton, P.G. Ferreira, A. Padilla, C. Skordis | arXiv, Published in 2012, 312 pages
142. Astronomical Image and Data Analysis
     J.-L. Starck, F. Murtagh | Springer, Published in 2006, 335 pages
143. Basaltic Volcanism on the Terrestrial Planets
     | Pergamon Press, Published in 1981, 1286 pages
144. Vision and Voyages for Planetary Science in the Decade 2013-2022
     | National Academy of Sciences, Published in 2011, 410 pages
145. Cosmology
     James Schombert | University of Oregon, Published in 2008
146. From Disks to Planets
     Andrew N. Youdin, Scott J. Kenyon | arXiv, Published in 2012, 70 pages
147. Cosmological Evolution of Galaxies
     Isaac Shlosman | arXiv, Published in 2012, 88 pages
148. Hubble Space Telescope: Discoveries
     | NASA, Published in 2012, 128 pages
149. Amateur Telescope Making
     | Springfield Telescope Makers Inc, Published in 2018, 428 pages
150. Superstring Cosmology
     James E. Lidsey, David Wands, E. J. Copeland | arXiv, Published in 2000, 161 pages
151. The Foundations of Celestial Mechanics
     George W. Collins, II | Pachart Pub House, Published in 2004, 145 pages
152. Pioneer Saturn Encounter
     | NASA, Published in 1979, 45 pages
153. Advances in Global and Local Helioseismology: an Introductory Review
     Alexander G. Kosovichev | arXiv, Published in 2011, 86 pages
154. The Star Splitters: The High Energy Astronomy Observatories
     Wallace H. Tucker | NASA History Office, Published in 1984, 182 pages
155. The Birth and Death of Stars
     James Schombert | University of Oregon, Published in 2008
156. Astrochemistry: The Issue of Molecular Complexity in Astrophysical Environments
     M. De Becker | arXiv, Published in 2013, 62 pages
157. Dynamics of the Universe in Problems
     Yu. L. Bolotin, et al. | UniverseInProblems.com, Published in 2013, 113 pages
158. Views of the Solar System
     Calvin J. Hamilton | , Published in 2008
159. Space Nomads
     Leota Jean LaPaz, Lincoln LaPaz | Holiday House, Published in 1961, 199 pages
160. Frequently Asked Questions about Calendars
     Claus Tøndering | , Published in 2008, 65 pages
161. Cosmic Rays in Galactic and Extragalactic Magnetic Fields
     F. Aharonian, A. Bykov, E. Parizot, V. Ptuskin, A. Watson | arXiv, Published in 2011, 43 pages
162. Plasma Physics of Extreme Astrophysical Environments
     Dmitri A. Uzdensky, Shane Rightley | arXiv, Published in 2014, 56 pages
163. The Fundamentals of Stellar Astrophysics
     George W. Collins, II | W H Freeman & Co, Published in 2003, 494 pages
164. Origin of the Moon
     W. K. Hartmann, R. J. Phillips, G. J. Taylor | Lunar and Planetary Institute, Published in 1986, 781 pages
165. Inflation
     Marieke Postma | NIKHEF, Published in 2009, 53 pages
166. Introduction to Early Universe Cosmology
     Robert H. Brandenberger | arXiv, Published in 2011, 70 pages
167. The Universe in a Helium Droplet
     Grigory E. Volovik | Oxford University Press, Published in 2003, 532 pages
168. The History of Astrometry
     Michael Perryman | arXiv, Published in 2012, 52 pages
169. Moon Trip: A Personal Account of the Apollo Program and its Science
     Elbert A. King | Lunar and Planetary Institute, Published in 1989, 162 pages
170. Mechanism of the Heavens
     Mary Somerville | J. Murray, Published in 1831, 710 pages
171. An Expanded View of the Universe
     | European Southern Observatory, Published in 2011, 54 pages
172. Cosmos and Culture: Cultural Evolution in a Cosmic Context
     Steven J. Dick, Mark L. Lupisella | NASA, Published in 2010, 612 pages
173. A Photographic Atlas of Rock Breakdown Features in Geomorphic Environments
     Mary Bourke, Heather Viles | Planetary Science Institute, Published in 2007, 88 pages
174. Planetary Photometry
     Max Fairbairn | , Published in 2005
175. Habitable Planets for Man
     Stephen H. Dole | RAND Corporation, Published in 1964, 176 pages
176. A Handbook of Descriptive and Practical Astronomy
     George F. Chambers | Oxford At The Clarendon Press, Published in 1889, 756 pages
177. Introduction to the Theory of Black Holes
     Gerard 't Hooft | Utrecht University, Published in 2009, 49 pages
178. An Overview of the Solar System
     | Wikipedia, Published in 2013
179. On the Origin (and Evolution) of Baryonic Galaxy Halos
     Duncan A. Forbes, Ericson D. Lopez | MDPI AG, Published in 2018, 232 pages
180. Special Functions: Fractional Calculus and the Pathway for Entropy
     Hans J. Haubold (ed.) | MDPI AG, Published in 2018, 306 pages
181. Planetary Science: A Lunar Perspective
     Stuart Ross Taylor | Lunar and Planetary Institute, Published in 1982
182. The Story of Eclipses
     George F. Chambers | S. S. McClure Co., Published in 1909, 208 pages
183. Evolution of the Solar System
     Hannes Alfven, Gustaf Arrhenius | NASA, Published in 1976
184. Celestial Mechanics
     J. B. Tatum | , Published in 2008
185. Observing the Sky from 40N
     Roberto Mura | Wikibooks, Published in 2010, 86 pages
186. Cosmology for Particle Physicists
     U. A. Yajnik | arXiv, Published in 2008, 63 pages
187. Practical Astronomy
     George L. Hosmer | John Wiley and Sons Inc., Published in 1925, 314 pages
188. Cosmology: The Study of the Universe
     | NASA, Published in 2009, 38 pages
189. Introduction to Supersymmetry: Astrophysical and Phenomenological Constraints
     Keith A. Olive | arXiv, Published in 1999, 67 pages
190. A Review of the Universe: Structures, Evolutions, Observations, and Theories
     | universe-review.ca, Published in 2009
191. History of Astronomy
     George Forbes | , Published in 1909
192. Mag 7 Star Atlas Project
     Andrew L. Johnson | , Published in 2007, 21 pages
193. A Primer for Black Hole Quantum Physics
     R. Brout, S. Massar, R. Parentani, P. Spindel | arXiv, Published in 2007, 178 pages
194. The Virial Theorem in Stellar Astrophysics
     George W. Collins, II | Pachart Pub. House, Published in 1978, 135 pages
195. Understanding Galaxy Formation and Evolution
     V. Avila-Reese | arXiv, Published in 2006, 50 pages
196. Lectures on Astronomy, Astrophysics, and Cosmology
     Luis A. Anchordoqui | arXiv, Published in 2007, 41 pages
197. Astrodynamics: A Compendium of Orbitology
     | Wikipedia, Published in 2013, 334 pages
198. Astronuclear Physics: a Tale of the Atomic Nuclei in the Skies
     M. Arnould, S. Goriely | arXiv.org, Published in 2020, 100 pages
199. Planetary Rings
     Matthew S. Tiscareno | arXiv, Published in 2011, 82 pages
200. Supernova Cosmology: Legacy and Future
     Ariel Goobar, Bruno Leibundgut | arXiv, Published in 2011, 62 pages
201. Images of the Solar Upper Atmosphere From SUMER on SOHO
     Uri Feldman, at al. | ESA Publications Division, Published in 2003, 209 pages
202. The Telescope
     Louis Bell | McGraw-Hill, Published in 1922, 294 pages
203. The Cosmic Web: Geometric Analysis
     Rien van de Weygaert, Willem Schaap | arXiv, Published in 2007, 129 pages
204. Astronomy Notes
     Nick Strobel | astronomynotes.com, Published in 2010
205. Atomic and Molecular Processes in Astronomy and Planetary Science
     Geoffrey A. Blake | California Institute of Technology, Published in 2004
206. Why CMB physics?
     Massimo Giovannini | arXiv, Published in 2007, 179 pages
207. Mathematical Theories of Planetary Motions
     Otto Dziobek | The Register Pub. Co., Published in 1892, 314 pages
208. Star-Gazer's Hand-Book
     Henry William Elson | Sturgis & Walton, Published in 1910, 72 pages
209. From Cosmic Birth to Living Earths: The Future of UVOIR Space Astronomy
     Julianne Dalcanton, et al. | arXiv, Published in 2015, 176 pages
210. Guidebook to the Geology of Barringer Meteorite Crater, Arizona
     David A. Kring | Lunar and Planetary Institute, Published in 2007, 154 pages
211. Techniques of Radio Astronomy
     T. L. Wilson | arXiv, Published in 2011, 47 pages
212. When Biospheres Collide: A History of NASA's Planetary Protection Programs
     Michael Meltzer | NASA, Published in 2011, 542 pages
213. Gamma-Ray Bursts: Progress, Problems and Prospects
     Bing Zhang, Peter Meszaros | arXiv, Published in 2008, 87 pages
214. Introduction to Non-Baryonic Dark Matter
     Paolo Gondolo | arXiv, Published in 2004, 51 pages
215. Big Bang Nucleosynthesis and Physics Beyond the Standard Model
     Subir Sarkar | arXiv, Published in 1996, 156 pages
216. The Cosmological Constant
     Sean M. Carroll | arXiv, Published in 2000, 50 pages
217. General Astronomy
     Harold Spencer Jones | Edward Arnold and Company, Published in 1924, 392 pages
218. The Birth And Death Of The Sun
     George Gamow | Dover Publications, Published in 1940, 256 pages
219. Cosmology Primer
     Sean Carroll | preposterousuniverse.com, Published in 2012, 120 pages
220. Telescopic Work for Starlight Evenings
     William F. Denning | Taylor and Francis, Published in 1891, 372 pages
221. An Introduction to Celestial Mechanics
     Forest Ray Moulton | The MacMillan Company, Published in 1914, 437 pages
222. Large Scale Structure of the Universe
     Alison L. Coil | arXiv, Published in 2012, 43 pages
223. Lectures on Black Holes, Topological Strings and Quantum Attractors
     Boris Pioline | arXiv, Published in 2007, 103 pages
224. An Introduction to the Theory of Rotating Relativistic Stars
     Eric Gourgoulhon | arXiv, Published in 2010, 88 pages
225. Astronomy for Amateurs
     Camille Flammarion | D. Appleton and Company, Published in 1910
226. The Astrobiology Primer: An Outline of General Knowledge
     Lucas J. Mix, at al. | arXiv, Published in 2006, 79 pages
227. Handbook of Space Astronomy and Astrophysics
     Martin V. Zombeck | Cambridge University Press, Published in 2006, 780 pages
228. An Introduction to Galactic Chemical Evolution
     Nikos Prantzos | arXiv, Published in 2007, 46 pages
229. Through the Telescope
     James Baikie | Adam and Charles Black, Published in 1906, 303 pages
230. Solar Neutrinos
     V. Antonelli, L. Miramonti, C. Pena-Garay, A. Serenelli | arXiv, Published in 2012, 51 pages
231. Astronomy with an Opera-glass
     Garrett Putman Serviss | D. Appleton & co., Published in 1890, 154 pages
232. Voyager Encounters Jupiter
     | National Aeronautics and Space Administration, Published in 1979, 48 pages
233. Astronomical Discovery
     Herbert Hall Turner | E. Arnold, Published in 1904, 225 pages
234. Caldwell Catalogue
     | Wikipedia, Published in 2014
235. Introduction to Cosmology
     David H Lyth | arXiv, Published in 1993, 53 pages
236. Cluster Lenses
     Jean-Paul Kneib, Priyamvada Natarajan | arXiv, Published in 2012, 120 pages
237. The world according to the Hubble Space Telescope
     Mario Livio | arXiv.org, Published in 2008, 112 pages
238. An Introduction to Celestial Mechanics
     Richard Fitzpatrick | The University of Texas at Austin, Published in 2011, 216 pages
239. Solar System
     | Wikipedia, Published in 2012, 646 pages
240. Cosmology and Astrophysics
     Juan Garcia-Bellido | arXiv.org, Published in 2005, 76 pages