University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln

Norman R. Simon Papers Research Papers in Physics and

1986

Intercontinental simultaneous survey of the unique cepheid HR 7308 in photometry and radial velocity

Gilbert Burki Geneva Observatory, [email protected]

Edward G. Schmidt University of Nebraska-Lincoln, [email protected]

Armando Arellano Ferro Universidad Nacional Autonoma de Mexico, [email protected]

J.D. Fernie David Dunlap Observatory

Dimitar Sasselov University of , [email protected]

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Burki, Gilbert; Schmidt, Edward G.; Arellano Ferro, Armando; Fernie, J.D.; Sasselov, Dimitar; Simon, Norman R.; Percy, John R.; and Szabados, Laszlo, "Intercontinental simultaneous survey of the unique cepheid HR 7308 in photometry and radial velocity" (1986). Norman R. Simon Papers. 23. https://digitalcommons.unl.edu/physicssimon/23

This Article is brought to you for free and open access by the Research Papers in Physics and Astronomy at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Norman R. Simon Papers by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Authors Gilbert Burki, Edward G. Schmidt, Armando Arellano Ferro, J.D. Fernie, Dimitar Sasselov, Norman R. Simon, John R. Percy, and Laszlo Szabados

This article is available at DigitalCommons@University of Nebraska - Lincoln: https://digitalcommons.unl.edu/ physicssimon/23 1986A&A...168..139B Astron. cepheid Intercontinental Summary. stars: G. Received Key 4 scopes second star abundance. 6 3 HR 2 America. the velocity photometric been 1 out 7 5 implies least 10 Stellingwerf(1984), several (1980a, and are during Send 1. HR papers 1983), Geneva Instituto Konkoly Department Department David Behlen R Introduction BurkP, Three HR 1) fundamental 7308 the definitively. 7308 0 Evans words: is during offprint abundances applied ) © The van located a 7308 are b), aspects. (or the by following: Astrophys. the was Dunlap European (V473 February (HD Laboratory Population different Observatory, A Genderen pulsation E.G. Burki Breger (1980a, de in higher) constancy Observatory, past stars: is simultaneous analysis the organized requests HR favour and Astonomia, 180583, most of of in Its Lyr). Schmidt2, decade, mode last Observatory, Astronomy, Astronomy, et HR - six versions (1969, essential b), Balona 168,139-146 the overtone. 19, photometry probably al. period, 7308 (1981), The seven confirms of of II to: 7308 Percy different of V473 accepted Southern or results (1982), in CH-1290 a Physics, cepheid the G. because Box 1980, data the A. (1985), mean monitoring Universidad August of - characteristics, years. Fernie 1 Lyr) and Burki simultaneous mean ~490975 Arellano stars: the a However, first University University 67, in Box that were countries Burki (50 classical 1981), June - radius (1986) Ford Baade- University has and/or Simon this Sauverny, 1525 The radial overtone (1982), radius. photometry ± 1984 cepheids 360, the Observatory obtained interested 15 2, (1984), ± Percy in cepheid Ferro\ (1981), Budapest constancy Nacional star larger cepheid R 1986 Wesselink the O~OOOOOl., (1985), Richmond on photometry velocities of of that in 0 Arellano summarized , Toronto, Sofia, cannot the Europe possibility of has Switzerland et - 41 Henriksson Burki by it J.D. than is Nebraska stars: Auvergne al. many unique ± pUlsating a is XII, using Autonoma exceptional A. of normal (1979), 11 method was Ferro Fernie\ pulsating yet Hill, survey 30 and and Ivanov the and variable R Toronto, Hungary observers • R 0 stable from be ten that cepheid and 0 , ON Mayor (1984), period (1986), Provided North Lincoln, radial (1980, in Percy . ruled 32 solar have tele­ The D. the the the Str. de L4C ± in at in - ON Sasselov radial Mexico, of 5, 4Y6, This was NE closely Thus, last intensity is tude that significantly of 35 ably instability werf, the (at conclusions amplitude calculations larger 15. Mayor, thesis between 34 a and Ferro 1126 M5S minimum normal the km the ± least 2) 4) 3) i) iii) 5) 6) 7) ii) 8) From by In variation 68588-0111, two distance 2.3 of 5 is Canada not periodic, 5 1984), , a HR (1984) 04510 s The The The Sofia, The The In that Concerning pulsation. than an lAl, R radial N.R. not an spaced -1 the the km star 1980), velocity the 0 maxima of the due unique the interaction this 7308 , strip. (June, variation pulsation instability mean star shape amplitude various due light the the s Mv 30 Canada and on 2nd determined -1 Simon with by entering NASA Astrophysics Mexico, determinations: d HR to of velocity, discrepancy or R0 non-linear frequencies. to star offers = the shows to (Jul.-Sept. Auvergne the the curve, becomes USA one), value at of time. (August diagram, 1985) the -3.1 implies the 2 the pulsation possible , is least existence the shape are: between in J.R. the D.F. sun, or of of beating when a normal mean of Thus, is the ± and radial Ro classical the pulsation leaving possibility the quasi-periodic, effects the simply asymetrical P 0.5 a (1986». important on 1981 1982). of the last = ercy (radial) mechanisms a fundamental the radius mode radial the Burki limit and the pulsation velocity of 20R value between solar velocity star 6, and maximum acting a the last sinusoidal variation The (i.e. value ASTROPHYSICS d and 0 companion. varies cycle ASTRONOMY of pulsation of lies velocity = ,M et Ro, abundancy. of June instability discrepancies minimum massive) with time HR studying, L. 810 and on al. Ro two curve, v of and clearly Data absolute = variation invoked Szabados (non-linear by the Ro (1982) 7308: 1985) around mode. ~~ggpc, increasing of light total elapsed -1.8andd oscillation convection when AND curve at driving originate amplitude in and cepheid, to System strip least in under total is a curves amplitude obtained magnitude The to the the high 20 does the certainly 7 and about of can between mechanism explain (Burki a R0 amplitude. the dynamical amplitude amplitude same red the modes debate diverging factor = (Stelling­ Arrelano be overtone not with a is implies 380pc. ampli­ 1400d. radius of hypo­ noted prob­ Ro vary star, also was and the the Mv the the of of = is 1986A&A...168..139B 140 authors Table Arellano surements Coffin origin 26.765 35.687 34.673 34.620 32.667 32.660 32.617 32.581 30.680 30.630 29.629 26.866 26.672 25.866 25.772 24.913 24.888 24.692 25.606 24.735 46.699 45.734 44.797 41.373 21 39.660 37.622 36.605 34.722 34.640 34.615 32.649 32.580 32.344 30.607 39.621 29.677 26.890 26.836 26.799 25.839 25.740 25.673 25.640 24.820 24.712 29.581 26.701 26.633 26.598 25.891 25.804 21.624 45.673 43.735 41.367 25 32.618 30.659 29.655 42.665 t-t .638 .708 © 1. of (PE), o Differential are time Ferro European with Sasselov Schmidt is (AF) respect to = -.123 -.311 -.226 -.263 -.096 -.281 -.184 -.293 -.235 -.086 -.096 -.249 -.161 -.091 -.175 -.206 -.063 -.092 -.248 -.223 -.264 -.209 -.175 -.176 -.200 -.275 -.288 -.095 -.092 -.290 -.205 -.153 -.143 -.089 -.230 -.149 -.248 -.201 -.091 -.111 -.281 -.278 -.187 -.112 -.258 -.284 -.255 -.270 -.308 -.256 -.106 -.117 -.247 -.211 -.091 - -.195 -.22 -.095 -.268 -.190 6.V and Szabados magnitude .113 HJD (SA), (SC), to Southern 9 HR 2445900. Fernie Percy Author 7280. V SC 5C PE PE PE PE AF AF AF AF sc SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SZ SC 5C P[ PE PE PE PE PE PE PE PE AF AF AI' AI' SC SC SC SC SA 5C 5Z PE FE PE sc FE FE FE FE FE FE (FE), mea- (SZ) The The and Observatory (FE) authors Table ments origin 24.888 24.692 21 39.621 32.660 32.580 26.866 26.836 26.799 26.672 26.633 26.598 25.866 25.839 25.804 25.772 25.673 25.640 25.606 24.913 24.820 21.624 26.765 24.735 37.622 36.605 34.615 30.630 32 26.890 25.740 25.708 24.712 26.701 25.891 t-t .638 .618 of 2. with o are time • Differential Provided respect Schmidt is to 6. = .116 .099 .127 .104 .148 .145 .138 .082 .085 .114 .128 .104 .094 .141 .131 .117 .144 .098 .118 .137 .124 .123 .104 .094 .141 .142 .145 .115 .106 .112 .151 .141 .101 .148 .102 (b-y) HJD to (SC) b HR by - 2445900. y and 7280. Author the measure- SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC 5C FE FE SC SC SC SC SC FE FE FE FE FE Fernie NASA The The Astrophysics surements The Table The Ischi terisk 24.437 24.539 24.518 24.396 24.501 24.371 24.588 24.570 24.473 24.595 24.581 24.555 25.432 25.410 25.393 25.379 25.352 25.332 25.537 25.482 25.468 25.555 26.364 26.348 25.596 25.567 25.512 25.440 26.472 26.458 26.438 26.414 26.319 25.537 26.334 32.608 32.427 26.602 26.559 26.506 26.386 27.315 26.591 33.507 32.587 26.540 27.331 37.554 33.606 33.581 27.394 37.592 t-t origin measurement is 3. due Radial o were of to time * Sasselov. Data velocity obtained -16.99 -17.98 -16.29 -15.06 -17.97 -11.90 -13.97 -12.71 -15.61 -16.43 -19.30 -11.39 -12.06 is -23.68 -22.72 -21.12 -20.02 -13.23 -14.27 -23.81 -23.00 -23.92 -18.89 -11.68 -22.94 -23.60 -23.23 -23.88 -23.00 -21.94 -10.08 -23.93 -23.29 -10.11 identified -6.66 -7.14 -7.89 -7.43 -7.18 -6.90 -8.19 -8.14 -7.75 -6.82 -6.68 -8.33 -7.08 -7.31 -7.36 -9.43 -6.60 -9.44 to Vr System = The measurements. HJD by other Burki by 2445900. an mea- and as- 1986A&A...168..139B in important to Tables HR this f(t) (PE) Tables) data given 2. measurements by (Bulgaria). (Bulgaria) at for collected Table David the with by CORAVEL fitted L1(b Haute-Provence Konkoly HID the San Observations A A3 A Al n a

2[rdJ A2 Al ¢3[rdJ A_ A 0 A 1jJ =50±15R a R - f E mean values 0 l[rdJ ~ res 0 q,y, on 6. we 5. © radius The Same t the A radius retain n + European in - and n12, results to Table phase as -0.009 -1.816 -0.1825 amplitude G (0.010) only Ro, f) 0.1006 0.682 0.0012 0.0124 0.010 0.021 0.022 0.008 0.005 0.014 the Table 0.007 6. 14.5 1. 1. is t-t of differences the 3.5 ratio the 94 Remember 81 50 very the 0 slope 4 Southern t.v ! ! ! ! ! :!: ± other ± ± ± ± ± ± = but 15 61 28 Balona f e. 0.0018 0.202 0.0025 0.025 0.0025 0.0025 2.009 1 high 8 7 2 4.0 0.01 0.03 0.002 2.1 21 15 of The A (SC) (Tot) (SA) (AF) (S2) (PE) (FE) for R value flux to IjJ of @ in that rd. rd. = the and Stobie uncertainty the 28 the to q,b-y Observatory for time the surface radius large the - various interval q,y, -1.709 Balona time (1979) 0.1191 0.0292 0.0050 0.287 -4.157 0.0015 0.0067 0.0043 0.0035 brightness-(b variation on + quantities Ro interval nl2 t method - t.(b-y) and 0.005 ! ! ! ! :!: ! ± (and 1. 1. 17.9 t-t and to 3.6 • and 0.204 0.0010 0.035 0.0010 0.0007 0.691 0.0010 98 87 63 Stobie = 28 35 0 Provided 7 case. - also ex 21 for ± ± ± ± ± ± = are the (SC) (Tot) (FE) = y) 0.003 8.4 0.03 0.04 3.6 33 21 to the 47 to This tities tion, method Aq, 32 two IjJ ± 47 = = by according time value are 10 q,y 1.94 to RG the important -14.644 - the -2.114 -4.024 0.216 ± is 8.463 1.491 0.044 obtained 0.415 q,b-y 0.03rad NASA measurements compatible to ~ V :!: ± ± Balona ! ± ! :!: r for 52 q,y 0.042 0.030 0.005 0.028 0.042 0.102 0.042 by = Astrophysics the - (Tot) 1UO Burki q,B-Y at and identification made the ± et Stobie 2° = = al. 1<7 during -0.13 -0.021 (1982) level (1979b, Data of ± summer with by ± the 0.04rad 0.006 applying 1980), pulsation the System 1980. in value two phase the In mode: quan­ Ro addi­ same 143 = 1986A&A...168..139B 144 WX 3.2. radius by (integration (parabolic from for and IjJ log In LI mean not by photometric both short Ro equation applying LIRe S2 of 3.3. Table tainties value method Ro LlV ficient or a of In Recall where of ef> loop < Balon the the LI(b this = LIef> a this Linear Parabolic = Torr results the must = 2 in from 140° Version /aR~) Version values polynomial time i= the 41 L time bLl(b fit radius 7. n phases b opposition from and - b case, into © that 1 and linear case, on a for is ± (LIRe, is Values y) parabolic a LIRe be is for and intervals. the -1 a European and from interval, similar Ro IjJ llR0 evaluated - at valid: a around the the the negative both constant, of of Burki of data Ro indicate the (see determination straight at y) Stobie the on and relation are - linear) the Burki colour Ivanov general two equal an of curve. results classical LlRo,)2/n LlR photometric phases Bevington, with and so t-t method quadratic radial curve Ro et LlRo iterative both The time (1979a) o 37 47 large in and by 0 line. that unique . of index radius (Jr.s al. X2 (1984) the It in assumption Table the ; ± ± error from Southern of curve. the least-squares estimations of is intervals = Benz velocity cepheids. R0 (1980) 19 14 HR 21 Thus, in (i.e. is classical equal case evaluated S2 to S2 (in is log procedure the on approximation for 1969). the R R to 7 on the from and n 7308 the the 0 0 with meaningless. As this (1982) /(J; gives of Torr the each Eq. case residual radii, 28 Ro obtained observations ... curve). best maximum we a radial t case: is cepheid is The As the LI R - - radial is (5) where are Observatory the that radially t cepheid. o V, see by solution, i.e. (b to , derived we fit - transforming is Burki where derivative b LI(b in the - velocity and values standard in Table to The LlR fulfilled for of - see, pulsation Ro t-t y) classification. agreement n = In - of y) likelihood expression LIRe LI = 40 for 47 pulsating is relation The relation 20 and the = from of o y) is V this the Meanwhile, 0, of the 34 Summer approximated ± ; ± and diagram to data) the and the (variation values 7, is Ro mean deviation Benz 43 21 55 case relation, 47 ± the number and the the calculated two LI(B following obtained 5 the with R R to between that on method and • eRa R0 0 0 quality uncer­ points radius of 90° (1982) taken 1980. cases - Provided from coef­ 47 LlRo = are the the the the (4) (5) by V) < in of of of 2 In Ro with R show accounted These relatively where 0 The agrees - the to to the 21 with such numerical 7308 less (See (Longer similar that (1981) J) VEL Cousins for ± (B ± ± find above Data to value usual with one are a normal made 0.003 0.004 0.003 - than well 28 respect an Figure HR of 2(J is by values V) conversion the applied and the any to found formula obtains lqgP). application). at period instability departure 7308. = System with 1980), However, since the about by system. those integration colour 0.64 derived for Fernie least other to 3 were Fernie theoretical previously the a according of this Thus Likewise, HR cepheids (Cousins and cepheid, for predicts 10 the mainly among Fernie excess, factor. values (1982) These deter­ mean value from strip. 7280 their days clas­ def­ are: fol­ the of 1986A&A...168..139B (b 5. (velocity) first-order Thus, in the the between suggesting E(B follows, as for falls above, an and The agreement and considerable age. is interval observations. the Using 5. 3.93(3.62); fundamental latter lows: mental modes might this the model ~, period, 6. at The log that that based small velocity has star Te no - given the Analysis present. Discussion = overtone data This Nevertheless, Comparing Simon g Fourier HR Te measured other a is the But we - uvby it to Y}o very overtone parameters = (1.56, reason 6110 is solar values based © the strength upon definitely may be f3 = V) for of be mode 7308 conclude implying the 1.8 effective the of by (b is if impinges the and 5850 f3 European this and comfortably interpreted = values hand, a 4>21(Velocity) normal K. Table phase that both (1985) HR - and between 2.6E-3), Simon fundamental (Sect. lie chemical of phase numbers Population two the strictly 0.25 pulsator. to (see with Y)o growth model the scatter For model K beyond and the Simon value. 7308 of Te VRI the consider linear are not temperature is given 4 f3 sets given would for lag, there there Burki that 4). distance constructed differences Hf3 Fourier or the and on and, is values decidedly fits fundamental (Ll8, values upon with the consistent definitely taken photometric supported In perhaps have composition of this from Given (Ll4»l. displayed rate as Because (1984) the compared present A the by the in models Lee among the is is given Southern = I photometry, be and addition, two period. appropriate colour this Tables LlE-2) the a no cepheid. for Arellano question model the 5.90(5.84}; overtone coefficients periods is Table needed star of (1981) to observed as conflict We Mayor, the (phase good redder in rather 4>21(light) parameters data-sets the higher star is Fourier 4>21(light), the work temperature of below the we a paranthesis, is with by therefore This too mode in 4 obtain this and to potential linear 4 were short-period analysis (light), the an an and have galactic to and and evidence fundamental Ferro the rather of red between other Fig. than lag), we small, than red (Ll4»l this 1980b). reconcile average. period, second-overtone scatter Observatory conflict (0.95, overtone. to overtone galactic whether decomposition suggests pulsation other 5, M growth and is edges. have described. non-adiabatic the Simon for the 4>21(velocity} M (1984). expected 2a is we expected one average very cepheids. confirms than = = for plane 2.0E-2). the not indicators. 4>21(Velocity) Table for = following the we may longer 5M So, for the suggesting colour calculated remains -0.24(-0.30). An sees Certainly, the component 3.82 classical zero-point or rates good those model pulsator. shall likely the and any The observed mode 0 one values the are excess easily have or , difference, not 5: for for that M that Although gravity L fundamental Teays abnormality 4>21(light) data. three (P, above use, suspects both from despite large-time­ unresolved significant, = 0, data, the the and the is values pulsation. pulsators. pulsation As relatively HR compute t/) of HR • cepheids a of 1000~, that L it and in so But period, period, funda­ period lowest star as (1983) errors Provided viable = f3 of about noted seems Table (Ll4>h value aver­ there what 7308 7380 cool The and and 398 fol­ the the the the the for the on = is (i.e. example, face are logg In pulsation are established out and Clearly, Table log 2.44 tion mental velocity tion (see still for and of of are a disk, However, higher) ulation by ability values ..... '1:l high p:: " I'i H rIl <:: (J) co co the 0 the Table a The g a 2) However, In 3} 1) difficult in unknown Population fundamental by since log Burki for gravities 35 30 exists 25 20 45 40 I on factor low period = and 8. cepheid, analysis conclusion, The The Both, the Baade-Wesselink the Both, favour of overtone various of mode II g overtone 1.8 the the three the Value curves then, a space a in = the 8 of cepheid HR the and values period that mass number ± second and 2 are to basis a 1.8. of the NASA Astrophysics we radius of 0.2 (see to versions for of high 7308, much radius-period of determine of 1 the Meylan, phase velocities are HR I given Under ~5. the the have mean 4. pulsation of a the and mode is of of the and the of would Sect. a 1.3 1.6 0.9 0.6 1.8 2.3 3.0 overtone large above overtone, of Then, 2.8 in the the 7308 linear following classical Table but HR yet mass caution Fourier second these to to consider differences high the agreement M radius of the (or, Fourier 5). most obtained 1986b) 7308 six the value imply 0 accurately. and values, is the the in models values However, cannot hypothesis 8. corresponds cepheids overtone) for values and a at M other relation must cepheid (and classification is probable high Baade- Ro coefficient comments low of that 0 that least predicts right coefficients fundamental together log that for in with 4>21(light), the of for of radius be higher) metal of mass be possibilities the matter, R0 have various the Wesselink the On Sect. for it for 1.4 1.8 g Ro 3.7 0.9 2.8 2.1 4.7 excluded these pulsating this are mean exercised that a must various explanation to a a second. the since (from Data mass contents, star pulsation Population and are locations with no star Population radius overtone. 5 the HR two of ofthe first radius: are values other 4>21(velocity), be longer to mode, HR with the the the are values corresponding 20 7308 only main Baade-Wesselink in (i.e. method emphasized log be before System overtone) of light surface 7308 to period, normal the hand, overestimated the in - M in made: of g Ro fundamental about for undubitably respectively. on is conclusions 45 II the = R the II the second possibility and a as one > R0). the 2.24 the = cepheids 1.5 5.9 2.3 2.0 we 7.4 3.3 Popula­ 4.5 cepheid, 0.6 the galactic gravity gravity require a 30R funda­ values pulsa­ 35 10 radial (Ll4»l basis Pop­ rules vari­ used M that sur­ and For 145 R0 R0 (or 0 to 0. . 1986A&A...168..139B 146 References Arellano Auvergne, mode finitively are indebted ipation Balona, Breger, Balona, Balona, Balona, Bevington, to respectively time, unique by ship and of Laura Research Rozhen. versity Acknowledgments. an the 481 and York, the Soc. bridge Soc. 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