Errata so far for Zeilik & Gregory, Astronomy & Astrophysics, 4th ed, 1998 Section 2.3 Need to re-arrange equation 2-12, not equation 2-13, to get $v=sqrt(2) v_0 [(R_\oplus/h + 1)]^{-1/2}$ factor of 1.44 in Chap 2 - shouldn't it be 1.41 (sqrt(2)), not 1.44 ($3^{1/3}$)? p 25, Section 2-1C, the definition of subsolar temperature is ambiguous to students as to whether albedo is taken into account. See the sentence just before Eqn (2-5b) p 42, Fig 3-10 vectors drawn/labelled incorrectly http://www.strw.leidenuniv.nl/~pvdwerf/teaching/iaf/errata.html p 158, Section 8-1C, just before Eqn 8-17: The unit of monochromatic flux F(nu) is W s-1 Hz-1 area-1 (book omits per unit area!) p 161, Section 8-1C, after Eqn 8-25: The Lyman series has nb=1 with na>=2 (text has na>2) p 162, Fig 8-9: It shows Lyman alpha as n=1-3, Lyman beta as n=1,4 etc. Should be Lyman alpha as n=1-2, Lyman beta as n=1,3 etc. This is a whopper of an error. p 169, following Eqn (8-33), denominator can be found from the Saha equation $N_{j+1}/N_j$ etc. should have subscript i to be consistent with the preceding text Sec 8-5B Shouldn't typical rms velocity be v_p = (3kT/m)^{1/2} in a 3-D gas? p 213, sec 10-5, paragraph 1: This flowing gas, composed of approximately equal numbers of electrons and PROTONS (not photons), is a plasma... QUESTION: How can we tell the polarity of a sunspot? By the sense of circularly polarised light. p 213, end of Sec 10-4: The figures for the density in the solar corona and photosphere are in kg/m3, and best match values for the bottom of the corona, since the density goes down fast with radius. Credit John Castner 17 Oct 2007 for catching this one. The typo is that the n(corona) and n(photosphere) are MASS DENSITIES (kg/m3), not number densities! See http://www.physics.louisville.edu/williger/Pa307_links/pa307_sundensities.txt for details. p 222, Problems for Chap 10: 10.4 is a little ambiguous in that the ionization potentials for FeI and FeII should be given. The answer states that the higher chromosphere temperature is the reason for stronger FeII in the chromosphere, but this is because the temperature is much lower than the energy corresponding to either ionization potential. The lower density in the chromosphere has a secondary effect in that the recombination time is increased. On page 201, the authors might mention that 2 pixels per resolution element is Nyquist sampling. They might also say a few words about IR detectors. p 242, Sec 12-3A $v_r=30 M_p \sin i/(a^0.5 M_*^{1/2}$ The coefficient of 30 comes from using the planet mass in Jupiter masses, not solar masses. REFERENCE: http://instruct1.cit.cornell.edu/courses/astro101/java/Finding%20Exosolar%20Planets.htm p 252, Sec 13-1A, just before Equation (13-4): instead of calling kappa the atmospheric opacity per unit mass, since it has the dimension of area/mass, it would be better called the cross-sectional absorption area per unit mass p 291, Sec 15-2B, $n_e=10^9$~cm$^{-3}$, $n_H=10^3$~cm$^{-3}$ -- either $n_H$ is neutral hydrogen or the numbers are wrong. It's unclear. Usually I see $R_s\propto n_e^{-2/3}$. The nomenclature compared to pblm 15-11 is also unclear (recombination rate $\alpha=(2\times 10^{-19})$n$^2$/m$^3\cdot$s. In the text, $\alpha$ is a recombination coefficient in units of m$^3$~s$^{-1}$. P 299, Sec 15-3A, shouldn't $E_{thermal}=(3/2)NkT$? Pblm 15-11: In chapter (p 291), $\alpha$ is given as a recombination coeffiecient. Here it is given as the recombination rate. The students find that confusing. Also, sometimes leaving more than one factor to the right of a division bar might be confusing, especially with a dot between factors. Parentheses help. p 299, Sec 15-3A, just after Eqn 15-9: units are kg/m3, not just m In same paragraph, $10^{15}$~m is about 0.03~pc p 300, Sec 15-3A, Time Scale for Collapse: a=(1/2)R, not a=(1/2)r p 300, Sec 15-3A, Eqn 15-10: constant is $6.64\time 10^4$, as in next equation line p 300, Sec 15-3A, derivation of Eqn 15-10 - is off by $\sqrt{2}$ from what I think is right answer at http://en.wikipedia.org/wiki/Free-fall_time (then free-fall time is 94000 years) p 300, Sec 15-3A, Magnetic Fields, after Eqn 15-11: I get $(3\times 10^{15}/7\times 10^8)^2=1.84\times 10^{13}$, not $2\times 10^{15}$. So $B_f \approx 1800$~T, not $10^5$~T. p 301, Sec 15-3B produced on core $->$ produced in core p 308, pblm 15-11, recombination coefficient $\alpha=2\times 10^{-19}$~s^${-1}$ in problem, just half that value in text on p. 291. Students find that confusing. pblm 15-11 again: what stars have required magnitude? Does the problem mean stars with EXACTLY M=0.35,M=8.85 or those BRIGHTER than that limit? The answer in the guide is unclear. Appendix 3, Table A3-3: Earth's equatorial radius is given as 6387km, but it listed as 6378km in Table A7-1. =================================================================== Date: Thu, 23 Aug 2007 15:22:58 -0700 (PDT) From: John Castner Subject: Suspected errors in our 307 text To: williger@pha.jhu.edu On page P-4, the derivation given for the derivative of r-hat wrt theta in (P1-6) does not match the computation of v in (P1-10). I suspect the second term of the sum in (P1-10) is supposed to be r(theta-dot)(theta-hat). A. I AGREE. On page P-8, the line of text above (P1-63) refers to (P1-41), which bears no resemblance to (P1-63). I believe it should refer to (P1-45). A. I AGREE If I find other concerns or questions about the text, I will ask about them. John ================================================== In the answer key: 3-2, the azimuth for sunrise/sunset for latitude 35 deg N is 61/299 deg on first day of northern summer, and 119/241 deg on first day of northern winter. This is a little far off from 45/315 and 135/225 deg. 4-17b, the question asks, "What percentage of these gases in the atmosphere is BELOW 4200m? (Assume the content decreases uniformly for each gas.) The answers are given as fraction = exp(-h/H) where H is the scale height However, this is NOT the answer! The answer is fraction = 1-exp(-h/H), which comes from integrating P(h)=P(0)exp(-h/H) from zero (ground level) to some height h' 8-8, Boltzmann's constant in eV is 8.62e-5 eV/K, not 6.61e-5 eV/K. Doubling the ionization ratio decreases the ionization ratio to 1e-10 times its former value. (The wording is unclear.) 14-3, (a) the log N(m)-mag relation should be a STRAIGHT LINE, not a curve. The general obscuration plot should be a curve with a flatter slope. (b) The curves be concurrent in front of the absorbing cloud, have a lower slope for the absorbed case inside the absorbing cloud and then be parallel but offset behind (fainter than) the absorbing cloud. 14-11, the figure needed is 14-4, not 14-6! --------------------------- ASTRONOMY AND ASTROPHYSICS, Zeilik and Gregory, 4th ed. (1998 Thomson Learning Inc.) Some errata noted by George Schuhmann, U. Louisville crack grad student in Gerard Williger's class (compiled 3/23/2009) Greek and mathematical symbols are described in the Latex convention Location(page) Description P-12 rt col line 8 dropped - sign on rhs of the equation P-12 rt col line 12 "terms" should read "term" P-22 equations (5-12) and (5-13d) should divide by 6 since particles may be traveling in either + or - direction in each dimension P-29 rt col (4th line from bottom) should refer to Figure 8-14 rather than 8-14A P-30 rt col (bottom line) equation omitted the 1/c factor P-31 lft col (8th line from bottom) "$\omega_g$" should read "$\omega_s$" P-31 rt col (3d line from bottom) reference to equation P6-23 should read P6-15 38 text of Figure 3-4 should list Tropic of Cancer at 23.5$^\circ$ rather than 63.5$^\circ$ 55 Figure 4-4 reference at bottom right should be "Waning" not "Waxing" 68 lft col mid-way down reference should be to Equation 4-1 rather than 2-4 102 rt col (8th line from bottom) reference should be to "Section" 4-3 rather than "Equation" 103 lft col (6th line) lst term of equation should be $(7\times 10^4)^2$ rather than $(7\times 10)^2$ 111 Captions for Figures 6-12 and 6-13 have texts exchanged 170 rt col half-way down aggregate of atoms "interact" should be "interacts" 213 rt col 6th line in sec 10-5 "photons" should be "protons" 216 text of Fig 10-20 "drift toward" should read "appear closer to" [text of page 217 indicates that sunspots remain at the same latitude rather than moving toward the equator] 225 lft col line after eq. 11-2 $10^6$ should be $10^{16}$ 225 lft col 8 lines from bottom $\pi''$ should equal 0.01" rather than 0.001" 225 rt col 2d para of subsec B reference to Section 15-1 should be to 19-2 225 rt col 15 lines from bottom reference to Section 15-2 appears to be incorrect [possibly refers to Section 19-3 on moving-cluster parallaxes] 226 lft col line 2 reference to Section 15-3 should be to Section 19-3 228 lft col 2d line after equation "and the Planck" should be "is the Planck" 241 rt col 2d line from bottom "extrapolar" should be "extrasolar" 276 lft col line 9 "this century" should be "the twentieth century" in future editions 291 lft col mid way down ($\lambda\geq 92.2$ nm) should be ($\lambda \leq 92.2$ nm) 299 rt col 1st line of subsec A "showed" should be "shows" [it is still showing those basics] 300 lft col 4th line from bottom "center of the cloud" should read "center of mass of the cloud" 308 Problem 11 $n^2$ should be removed from the equation for $\alpha$ 333 text of Figure 17-1 second line should refer to "left" instead of "right" 367 lft col line 8 of subsec B "Must" should be "Most" 458 lft col $M_0$ preceding Great Attractor and in 4th line from bottom should use solar mass symbol 458 text of Figure 23-14 $10^0$ should be $10^\circ$ 509 rt col 2d para line 2 "for" should be "For" 510 rt col 2d para line 4 "compute" should be "computer" 513 rt col line 5 of Sec 26-8 "an" should be "can" A-13 Use the standard Periodic Table so valence groups are displayed as customary in chemistry A-36 lft col line 8 "equioxes" should be "equinoxes"