COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 660 Konkoly Observatory Budapest 1972 April 14 New and Suspected Variable Stars in VSF 193 Abstract. - Identification charts and tables are given for 275 variable or suspected variable stars in Sagittarius, together with a summary of the work thus far accomplished in VSF 193. Nearly forty years ago at Harvard College Observatory I discovered or re-discovered over 500 variable stars in VSF 193, centered at 18h23m -23.3deg in Sagittarius. The positive-negative superposition method for discovery was used. Each of eleven plates of the MF series (ten-inch Metcalf refractor, f.l. 45 in.) was compared with one of four positives, and five plates of the A series (24-inch Bruce refractor, f.l. 135 in.) with one positive. Before the examination of the variable stars had progressed far, Dr. Shapley discontinued the project, and my brief resume of what had been accomplished was incorporated into the Shapley and Swope (1934) report on variable stars in low galactic latitudes. Many years then elapsed before the work was resumed, mainly during the summers since 1957 at the Maria Mitchell Observatory with the help of young women college undergraduates whose trainee program was supported largely by successive grants from the National Science Foundation. Results to date on periods or types of variability have been published in the following sources: Year Reference Number of Variables 1932 Bull. No. 890, Harvard Col. Obs., p. 13 1 nova 1934 Annals, Harvard Col. Obs., Vol.90, p. 187 18 1955 Astron. J. Vol. 60, p. 259 (Dishong & Hoffleit) 1 nova 1957 62 120 65 1958 63 78 20 1958 63 511 (Andersen) 1 nova 1959 64 241 6 1959 64 417 41 1960 65 100 20 1961 66 188 45 1962 67 228 12 1963 68 207 27 1963 68 253 (Houk) 1 1964 69 301 15 1965 70 307 24 1966 71 130 11 1967 72 711 12 1968 I.A.U. Info. Bull. On Variable Stars No. 254 1 1968 277 10 1968 312 8 1969 387 12 1969 I.A.U. Info. Bull. On Variable Stars No. 395 (Akyuz) 1 1970 474 1 1971 592 3 1972 617 6 In addition, in 1967 in Information Bulletins 228 and 231 Dr. Nancy Houk has given spectral classes of 137 of the previously published red variable stars. The total number of variable stars already published in this survey is 360. All of the remaining variables or suspected variables found in VSF 193 are listed in Table I.* Finder charts are given for all of these. Included are stars from the above references published since 1964, and a few other variable stars that happen to occur on the same charts as the new variables. The charts were traced by Ruthe Seifart from the enlarged projections of MF plates. The original scale of the plates is 167"/mm while the charts represent areas approximately 10' x 10'. In all cases South is at the top and East to the right. * See p. 18 ff. In Table I the first column gives the number of the chart. If more than one variable is marked on a chart, the letters a, b, etc., are assigned in order of increasing right ascension. The magnitudes given depend in most cases upon 200 to 500 plates, although in a few instances only some 20 plates of the A series were usable for stars with bothersome optical companions, very faint stars, or stars close to the edges of the field. The late-type spectral classes were estimated on infra-red objective prism plates of the Warner and Swasey Observatory (Case-Western Reserve). Those underlined were estimated by myself; the others by Nancy Houk who classified all of the red stars with maxima 14.5 mag. pg. or brighter in a selected 20 square degree area. In a few instances these late spectral types may refer to a companion star instead of the variable. For five of the variables subsequently determined to be RR Lyrae type, spectral class M had orginally been assigned. In two of these instances the Bruce plates revealed the faint red companion. Three suspected variables of small amplitude were at the time of discovery supposed to be red stars by virtue of their somewhat more fuzzy appearance than the images of the comparison stars on blue-sensitive plates. Eventually a check on the objective prism plates for the Henry Draper Extension revealed that all three are planetary nebulae. On re-examination of the direct plates, I would still suspect these stars of slight variability, but this may be a spurious photographic effect. The only similar instance found in the General Catalogue of Variable Stars is for V567 Sgr, found by Swope (1938) on similar Harvard plates. While she found a variation of about one magnitude, the General Catalogue indicates that the object is non-variable (cst). Herbig (1950) found no evidence for either spectral, radial velocity or light variation and therefore inferred that the Harvard observations may represent only instrumental effects. Liller and Shao at Harvard are obtaining UBV magnitudes of nuclear stars of planetary nebulae, a few of which are being especially watched because they have been suspected of variability. Among the stars in Table I unclassified as to types of variability, 83 appear to have M-type spectra. The majority of these have small amplitudes which may, however, be affected by companions. Since a high percentage of stars with late type spectra is expected to be variable (Houk 1967), these merit further investigation with higher resolution. The next to last column in Table I gives one of three types of entries: the final designation of already named variables; the reference to a previous publication for published variables not yet listed in either the General Catalogue, or the Catalogue of Suspected Variable Stars; or, for the heretofore unpublished variable stars, code letters indicating the observers who estimated the magnitudes. Footnotes to the Table identify the observers and give the years in which they participated in the project, and the colleges from which the summer student assistants came. In the final column, an asterisk refers to a separate footnote, while the letter c indicates that the star appears to have an optical companion which might affect the magnitude estimates. Close companions are prevalent in this crowded field. Among the more than 500 variable stars examined, 168, or nearly a third, have companions noted either on the limited number of available Bruce plates, which have the more open scale of 60"/mm, or they were inferred from the small amplitudes and flat apparent minima of the light curves found for Mira-type stars. Undoubtedly 33% is only a lower limit to the percentage of variables somewhat affected by unresolved companions. The distribution of the variable stars according to the type of variability and apparent magnitude at maximum is shown in Table II. The stars of undetermined type are separated into two categories: those known to have late spectral classes, and all others. Both groups are then sorted according to amplitude of apparent variation. Table II includes five variables discovered in this survey but not included in Table I because they have meanwhile been independently discovered and published elsewhere (V 1176, 1182, 1187, and 1601 Sgr). In the groups with apparent amplitudes less than 0.5 mag the variability has, of course, in every case been questioned. In all such cases more than one observer has conceded the probality of variation on the plates examined. Table II indicates that the maximum frequency of the variables of all types is close to magnitude 14.0 at maximum light. This is more indicative of the optimum magnitudes for discovery on the MF plates, than of cosmical significance. For other than the long period variables and high-amplitude semi-regular stars, the numbers discovered in each category have been too few to warrant analyses for the completeness of discovery. Table II. Distribution by Type and Magnitude at Maximum Magnitude: 10 11 12 13 14 15 Total Type Var. M 3 19 99 70 12 203 SR 2 6 28 32 5 73 RV 3 3 3 9 L 1 3 9 1 14 C 4 1 1 5 3 4 18 RR 1 4 14 21 5 45 UV 1 1 UG 1 0 1 4 6 RCB 1 1 1 1 4 I 7 10 13 30 N 6 3 9 E 5 1 4 7 14 13 44 Total Classified 15 6 14 56 182 161 22 456 Unclassified: M-Type Spectrum AMPLITUDE <0.5 5 5 0.5-1.0 3 6 17 24 3 53 1.0-1.5 1 1 6 5 13 1.5-2.0 1 1 2 >2.0 2 2 Total 4 8 31 29 3 75 Not M-Type Sp. 0.5-1.0 1 2 11 9 4 27 1.0-1.5 1 2 9 12 1.5-2.0 1 2 2 5 >2.0 3 1 4 Total 1 3 17 21 6 48 GRAND TOTAL 15 6 19 66 230 210 31 579 Even for these the estimates are not very meaningful except for indicating the feasibility of continuing the search on the available plate material. For the discovery of the long period variables, only three pairs of the MF plates used can be considered both as "independent" and with time intervals sufficiently long for the detection of variables of these types (Table III). Table III. Independent Pairs for the Detection of Long Period Variables. Pair Date of positive Date of Negative Interval 1 5 September 1925 21 August 1928 3 years 2 25 August 1924 28 April 1930 6 3 30 August 1929 10 June 1931 2 The numbers of long period variables found once, twice and three times among these three pairs are given as a_i in Table IV, where A represents the total number of such variables found on the three pairs of plates, w is the probability of discovering a variable once, and N is the total number of variables inferred from these data. These values are based upon the method published by van Gent (1933). Under "MF" are the numbers actually found on all of the MF plates intercompared (11 interdependent pairs) and under "All" the total numbers found on both MF and A plates. The A-plates, however, cover only about half of the area of the MF. The values N are ostensibly the number one would expect to find from an exhaustive search of the particular type of MF plate material used. The MF plates actually searched would thus appear to have revealed about three-fourths the expected numbers. But with the better Bruce A-plates considerably more are discernable. The discovery probabilities appear to decrease with fainter magnitudes. This is to be expected from the greater uncertainty in identifying faint blended images in crowded regions as those of long period variables. Table IV. Discovery of Long Period Variables. Mag. at A a_1 a_2 a_3 w N MF All %MF Maximum 12-13 14 8 4 2 0.24 25 17 24 68 13-14 38 33 4 1 .14 105 87 121 83 14-15 19 18 1 0 .07 95 67 88 70 Total 71 59 9 3 - 225 167 233 74 That there is no obvious correlation between period and magnitude at maximum for the long period variable stars found in this region is shown in Figure 1. The maximum concentration appears to be near a period of 240 days and magnitude 13.8. If there were no obscuration and the Wilson-Merrill (1942) period-luminosity relation were to hold, this would indicate a maximum concentration of these stars at about 7 kpc - an upper limit to their mean distance since many of the magnitudes must be appreciably affected by obscuration. [FIGURE 1] (Open circles for stars in the less obscured regions) The distributions by period and uncorrected distance are shown in Table V. Here the zigzag line indicates the approximate limiting distances for detecting variables 14.5 mag. at maximum. On the Nantucket plates this is effectively the limiting magnitude for the recognition of variables as belonging to the Mira type. At the mean galactic latitude of the region, -7.5deg, the stars in the more transparent regions and having periods less than 200 days can be seen to distances beyond the galactic center. On the other hand, very few long period variables have been found out to be 3 kpc, the practical limit for the discovery of the less luminous stars with periods of 400 days or more. The long period variables have been sorted into two categories according to the relative overall appearance of obscuring matter in their immediate surroundings. If the variables were uniformly distributed in space we would expect for each period an approximately three-fold increase in their numbers with increasing magnitude. The small numbers of stars for magnitudes brighter than 13, compared with those 13-14 mag. (Table VI) confirm that the density is not constant but increases appreciably as we approach the galactic center. Already at 14-15 mag., however, the numbers level off, mainly because of observational selection effects. The faint limiting magnitude of this survey is still too bright for extinction effects to be clearly indicated (as in Wolf-diagrams) by differences in magnitude-frequency distributions between the obscured and relatively clear regions. Table V. Frequencies of Periods and Distances. 200 250 300 350 400 450 500^d Total kpc 1 0 0 2 1 0 1 1 1 6 2 1 0 3 4 2 3 0 0 13 3 --------------- 0 6 8 8 2 | 1 1 1 27 4 -----| 0 7 16 7 | 1 1 32 5 -----| 2 9 16 | 3 30 6 | 3 15 10 | 4 32 7 -----| 7 14 | 5 1 27 8 | 6 9 | 4 19 9 | 8 6 | 3 17 10 -----| 5 | 5 10 11 | 5 | 3 8 12 | 6 | 0 6 13 | 4 | 1 5 14 | 2 | 2 15 ------| 1 1 16 Total 50 75 67 28 5 6 2 2 235 Table VI. Period-Magnitude Distributions. Period * Mag: 12 13 14 15 16 Total 150-200 C 0 1 16 10 1 28 O 0 2 11 9 1 23 200-250 C 0 6 20 15 0 41 O 1 4 16 13 0 34 250-300 C 2 0 17 7 4 30 O 1 2 17 17 1 38 300-350 C 0 1 7 2 1 11 O 0 2 6 6 2 16 >350 C 0 0 3 1 0 4 O 0 2 3 6 1 12 Totals C 2 8 63 35 6 114 O 2 12 53 51 5 123 O+C 4 20 116 86 11 237 *O, obscured; C, clear Table VII compares the average apparent magnitudes, periods and distances in three magnitude groups. Here kpc refers to the average of the distances whereas kpc(P) is the distance corresponding to the average period. The discordance between these values is an indicator for the dispersion in the distances, which range from 2 to 15 kpc. The difference between the mean distances of the obscured and relatively clear regions reflect mainly the differences in average period-length. Table VII. Average Parameters, in Three Magnitude-Intervals. Mag. Interval: 12-13 13-14 14-15 Clear Obscured Clear Obscured Clear Obscured n 8 12 64 58 37 54 m 12.4 12.5 13.5 13.5 14.3 14.3 P 222 278 246 241 227 259 kpc 4.2 3.8 6.0 5.6 9.4 7.6 kpc(P) 3.8 2.7 5.3 5.4 8.9 7.1 The frequency distributions by period are shown in Figures 2a (clear regions) and 2b (more obscured), while Figure 2c shows the frequencies of the uncorrected distances. The stars in the same line of sight as the dark nebulosities have an apparent average distance of 6.2+-2.0 kpc, not significantly different from the average of 7.1+-2.1 for the stars in the more transparent looking regions. Two compensating effects may account for this coincidence. In the more obscured regions one would expect the distances uncorrected for absorption to appear greater than in transparent regions. On the other hand, many of the actually more distant stars in the dark regions are too much obscured to be seen at all; whence the average distances in the obscured regions refer to a group of stars more nearby than those in the clear regions. Moreover, the separation of the two groups may not be sufficiently definitive. Although approximately equal numbers of stars are represented, it is [FIGURE 2] significant that the relatively transparent areas occupy less than one-third of the total area of the field. The variables ascribed to obscured regions frequent mainly the dimmed boundaries between the clear regions and the lanes of densest obscuration, generally avoiding the darkest parts of the lanes altogether. The entire field is very complex in appearance. When the stars are sorted by period (Table VIII and Figure 2d) the average distances in the two groups again show no significant differences. The relatively nearby stars of longer period dubiously suggest that the obscured average more distant by 0.5 kpc, corresponding to an extinction of 0.3 mag. The stars at these distances are on the order of half a kiloparsec below the galactic plane. The more distant stars are farther below the plane (Z in Table VIII) and would therefore be affected by little additional absorption; but they would be expected to confirm at least the absorption found at shorter distances, if real. Table VIII. Average Parameters for Equal Intervals in Period. Relatively Clear More Obscured Interval n P m kpc Z n P m kpc Z days 150-200 28 181 13.8 10.2+-.5 1.3 23 176 13.8 10.4+-.5 1.4 200-250 41 223 13.7 7.2+-.2 0.9 34 224 13.6 7.1+-.2 0.9 250-300 30 272 13.9 5.8+-.3 0.8 38 276 13.8 5.2+-.2 0.7 300-350 11 330 13.8 3.9+-.3 0.5 16 319 14.0 4.5+-.3 0.6 >350 4 438 13.8 2.6+-.2 0.3 12 422 13.9 3.1+-.3 0.4 Future work in this region should stress the importance of obtaining accurate magnitudes of the variable stars in different colors, for the purpose of evaluating extinction. My associates and I have been deeply indebted to the U.S. National Science Foundation under whose support the major part of this investigation has been accomplished. I wish also to express thanks to Ruthe Seifart for her meticulous preparation of the identification charts. Dorrit Hoffleit Maria Mitchell Observatory Nantucket, Mass., U.S.A. April 1972 References: Herbig, G. 1950, P.A.S.P. 62, 211. [BIBCODE 1950PASP...62..211H ] Houk, N. 1967, Astron. J. 73, S99. Liller, W., Shao, C. 1970, Astron. J. 73, S103. 1971, Bull. Amer. Astron. Soc. 2, 205. [BIBCODE 1970BAAS....2S.205L ] Shapley, S., Swope, H.H. 1934, Ann. Harvard Coll. Obs. 90, 197. Swope, H.H. 1938, Ann. Harvard Coll. Obs. 90, 207, H.V. 7117. Wilson, R.E., Merrill, P.W. 1942, Ap. J. 95, 248. [BIBCODE 1942ApJ....95..248W ] Table I. Variables and Suspected Variables in VSF 193. Var. R.A. (1900) Dec. Max. Min. Type Sp. Obs.# R* Ident. 1 18h 7m 4s -26d 33.'8 11.9 12.4 M5 A,Ro 2 7 50 -27 2.0 12.5 13.7 I? M5: Ku,T 3 8 30 -23 59.8 13.3 14.2 M5: A,Le 4 8 46 -18 56.7 13.4 14.4 SR? M7 A,H,W, * 5 9 30 -19 41.4 13.7 15.8 RV? A,BC 6 10 14 -27 39.0 14.6 15.5 M2: Ho * 7 10 23 -27 3.5 13.8 15.0 M3: Ho 8 10 24 -18 54.2 14.8 15.4 BC 9 10 45 -21 24.8 15.2 15.9 Sa c 10 11 0 -24 0.0 14.5 16.2 SRa V2331 11 11 9 -21 30.2 14.3 14.8 A,H 12 11 21 -26 29.6 14.0 14.8 M5 Ro 13 11 22 -25 57.0 13.5 15.5 SR M: T * 14 11 29 -27 51.7 11.1 12.1 SRa M2 V2513 15 11 48 -26 34.9 15.0 15.8 M: A,W 16 12 36 -23 58.8 14.8 16.2 A,Ki * 17 12 52 -27 34.8 14.5 16.2 M M5 V2520 c 18 12 59 -24 39.7 14.2 15.5 M7 T,P * 19 13 7 -25 44.4 13.5: 14.0: M8: T,P * 20 13 24 -26 19.0 14.7 15.8 M4: P 21 13 25 -24 56.2 12.7 13.5 M4 P,Do 22 13 34 -23 49.9 14.0 14.5 M6 A,T 23 13 37 -23 19.0 12.6 13.3 I M5 V2333 24 13 46 -23 56.9 14.5 16.0 SR M8: V2524 25 13 48 -26 43.5 14.0 15.4 RR P,W * 26 13 49 -23 31.5 14.5 15.2 E? M: H 27 13 50 -18 57.2 13.6 14.3 RR BC 28a 13 55 -22 15.4 13.8 16.0 EA V2525 28b 13 56 -22 10.0 12.4 13.0 E? M6: Jo,Se 29 13 56 -23 53.6 14.3 15.4 I? M5: A,L 30 14 2 -22 58.2 13.6 [15.0 EA V2527 31 14 8 -23 23.1 12.8 13.8 I? M7 Z 32 14 8 -27 19.4 14.3 15.0 A,Se 33 14 16 -28 5.6 14.3 14.9 A,Se c 34 14 18 -23 59.4 14.9 [15.6 M A,Ki 35 15 9 -23 8.4 14.3 16.3 SRa M: V2534 * 36 15 23 -23 56.2 14.7 15.7 M7 A,Ki 37 15 27 -22 22.8 13.3 13.9 M5 A,We 38 15 50 -22 31.2 15.6 16.4 M6 A,We 39 15 56 -23 36.2 13.5 14.7 M7 R 40 15 55 -23 57.1 13.7 14.3 M: Ki 41 16 1 -24 25.1 14.2 15.4 SR? M5 T 42 16 16 -23 18.8 14.3 [16.2 E vS,H * 43a 16 19 -27 34.3 13.7 14.6 M1: A,Se c 44 18h 16m 22s -25d 10.3 14.2 15.4 RV? M5 H,De 45 16 23 -22 40.0 13.5 14.3 EW? R,We * 46 16 46 -23 40.0 12.2 12.9 M2: Z 43b 16 49 -27 28.4 12.2 [16.5 M M: WW Sgr 47 16 59 -23 52.0 14.2 14.8 M4 R 48 17 2 -24 24.6 13.8 14.7 M2 P,H 49a 17 4 -24 41.1 14.7 15.2 M H,De 50 17 5 -25 29.6 14.9 15.7 M vS 49b 17 6 -24 40.2 13.3 15.1 M M6 V1868 51 17 18 -22 25.6 13.5 14.2 EW? We 52 17 28 -21 56.0 14.6 16.0 I? A,We 53 17 35 -23 32.1 15.0 16.2 M? M5: G 54a 17 37 -23 23.3 14.5 [16.3 M M6 V2332 * 55 17 38 -25 29.0 13.8 15.5 EA V2338 56 17 40 -21 33.6 14.3 15.2 A,As 57 17 54 -27 22.8 13.8 15.1 I? M6 Ro 58a 17 57 -25 57.1 14.1 15.2 I? M H 54b 18 3 -23 21.7 14.0 16.3 M M2 V2339 58b 18 8 -25 56.4 15.4 16.4 SR? M4 V514 59 18 17 -21 43.2 13.0 14.0 M2 Jo 60 18 18 -22 54.0 14.0 16.3 M M7 V2340 61 18 23 -22 21.3 14.0 15.5 SRa M V2542 62 18 25 -23 50.0 13.5 14.6 SRa M4 V2341 63a 18 26 -24 56.2 12.8 14.8 RV M: V2342 63b 18 34 -24 55.8 15.4 16.6 RRa IBV387 * 64 18 37 -23 22.9 14.0 [16.0 M M7 V2343 63c 18 42 -24 58.9 15.6 16.6 RR IBV 312 * 65a 18 47 -26 32.4 13.7 [14.5 M M7: V2543 66 18 50 -26 39.0 15.0 [16.0 M M: V2544 * 67 18 54 -24 26.6 14.9 15.8: M6: P 65b 18 56 -26 29.6 14.0 15.4 SRa M4 IBV 387 68a 18 57 -23 11.3 13.0 16 : M? M: vS,Z * 65c 18 58 -26 29.4 13.6 16.0: M M7: V1656 68b 18 59 -23 9.2 13.7 [16.3 M M2 V1657 69 19 13 -21 47.9 13.6: 14.5 L * 70 19 13 -22 17.6 14.3 15.0 M7 A,Gu 71 19 24 -22 14.4 13.1 13.7 A Gu 72 19 38 -23 15.4 11.8 12.4 Pd vS,L * 73 19 46 -24 25.0 15.0 16.0 RR? P,Wh * 74 19 58 -23 3.7 14.4 16.3 C V254epsilon 75a 20 8 -22 10.1 12.8 13.9 M2 Co 75b 20 10 -22 9.1 14.0 14.5 M: A,Gu 76 20 12 -23 13.5 13.1 14.0 I? M3 Z * 77 20 13 -21 16.8 12.5 14.3 RR B * 78 20 15 -24 17.5 13.5 14.8 C? L * 79 20 17 -22 16.4 14.4 15.1 M7 A,Gu 80 20 20 -23 18.0 14.7: 15.7: R * 81 20 21 -24 52.7 13.1 13.6 P,H 75c 20 23 -22 7.8 13.7 14.6 EA A,H 82 20 27 -22 5.7 14.5 16.4 M M3 V2548 83a 20 27 -22 49.6 13.8 14.6 I? M5 vS,H * 84 20 28 -27 58.3 13.0: 14.0: M2: St 85a 20 40 -24 14.6 14.8 16.0 E? P 85b 20 41 -24 17.8 13.6 14.1 P,H * 83b 20 45 -22 49.5 14.5 [16.3 M M8 V2345 86 20 45 -23 28.9 13.4 14.8: RR V2344 * 87 20 47 -21 29.4 14.8 15.9 A,As 88 20 48 -21 10.9 12.1 13.0 SRb M6 V2346 89 20 49 -24 21.7 13.6 14.3 RR? Co,P 90 20 54 -26 12.3 13.6 15.0 I? M6 H * 91a 20 54 -24 46.1 15.2 16.0 M2 P,Wh 92 20 56 -21 46.4 13.8 14.4 M3 A,Le 93 20 56 -24 59.7 14.2 14.7 M6 Sa * 94a 20 59 -22 21.1 15.0 [16.0 M V2549 95 21 3 -23 39.7 14.7 16.1 SR? M: G 96 21 3 -26 3.1 14.0 14.8 M: H 91b 21 8 -24 38.8 14.9 15.7 Ib? M8 P,Wh 97 21 14 -23 26.7 14.5 15.5 E? M2 G 98a 21 19 -22 6.5 13.6 14.1 M3: A,We 94b 21 19 -22 18.3 14.6 15.9 A,H * 99 21 21 -24 46.6 14.3 15.2 RR V2552 * 98b 21 27 -22 3.8 14.3 15.0 M6 A,We 100 21 31 -23 19.6 14.4 [16. M M: V2553 * 98c 21 33 -22 4.6 13.8 [16.5 M V1662 101 21 39 -23 53.4 13.5 14.5 M6 R 102a 21 41 -27 41.0 12.7 14.0 Ne? V1998 102b 21 43 -27 42.6 13.9 15.0 I? A,H 102c 21 44 -27 43.9 13.8 [16.0 M LP Sgr 103 21 53 -26 28.0 13.0 14.1 M6 H,St * 104a 22 2 -24 52.7 15.0 16.5 P 105a 22 3 -25 15.4 13.8 16.0 M4 P * 105b 22 7 -25 17.6 13.9 14.2 M3 P 106 22 14 -21 11.8 13.9 14.3 M5 A,Le 107a 22 16 -23 21.0 14.5 15.8 RV? M3 A,H c 104b 22 20 -24 55.8 13.6 16.5 M M3: V1664 108 22 21 -22 10.2 14.2 [16.1 M M8 V2557 109 22 22 -24 28.0 13.3 13.8 M5 P,H 110 22 23 -22 17.0 14.0 15.5 SR M3-6 V2558 * 107b 22 27 -23 16.6 14.1 [15.5 M M4 V2348 111 22 29 -22 23.4 14.4 15.2 M7 A,We 112 22 34 -23 4.4 15.9 16.5 A,We * 113 22 40 -23 35.4 14.4 15.0 I? M7 A,Se 114 22 45 -22 30.0 14.3 15.0 M5 A,Do 115 22 45 -25 51.6 13.8 15.5 I M6 V2350 116a 22 47 -22 5.4 14.8 15.3 A,Gu 116b 22 50 -22 3.6 15.6 16.2 A,Gu 116c 22 51 -22 3.4 15.4 16.2 RR A,Gu * 117a 22 53 -24 40.5 13.4 14.6 I? C St,Le c 118 22 53 -26 41.7 14.2 15.6 I? M0: Gu 119 22 57 -22 51.4 14.0 [16.0 M M8 V2562 * 116d 22 58 -22 10.2 13.8: 14.2: M: A,Gu * 120 23 4 -25 25.7 13.7 14.7 SR? M3-7 P,Le * 121 23 6 -23 53.4 13.3 13.9 M: A,H 122 23 7 -23 1.2 14.3 15.0 M4 A,H 117b 23 10 -24 37.6 14.2 [16.0 M M8 IBV 617 117c 23 11 -24 36.4 13.5 [15.5 M M: V2565 * 116e 23 12 -22 6.3 13.5 15.4 M M7 V2352 123 23 13 -20 52.6 12.0 12.6 M5 B 124 23 15 -22 36.8 14.3 15.2 RR? Bo 125 23 16 -24 49.7 13.7 14.1 M3 P,H 126 23 20 -24 27.9 13.6 14.1 Ib M5 V2353 127 23 24 -20 44.4 13.6 14.3 M: A,Le * 128 23 38 -24 41.9 14.9 15.9 P 129 23 39 -22 26.8 14.3 15.1 M7 A,H 130 23 49 -22 10.7 14.6 15.7 M: A,Wo 131a 23 54 -23 14.8 14.6 15.5 I? M8 Wo * 132 23 58 -25 38.0 14.1 15.3 RR V2569 131b 24 2 -23 19.3 14.7 15.8 M M6 IBV 617 * 133 24 2 -24 56.3 12.4 13.2 UV? M5 V2354 131c 24 9 -23 14.4 14.6 16.2 RR V2570 134a 24 10 -24 3.3 14.9 16.1 I M7 A,Wo 135 24 26 -22 27.6 13.9 16.6 M M3 V2357 134b 24 35 -24 2.0 14.5 16.0 RR? M2? A,Wo * 136 24 35 -25 13.5 13.2 13.7 St 137a 24 38 -23 42.5 13.9 14.5 I M5 V2358 * 137b 24 43 -23 42.8 14.3 15.5 RR Di,A * 138a 24 43 -24 54.5 14.3 15.0 M5 P,La 139 24 45 -23 9.7 14.5 15.9 M M7 V2571 140 24 46 -26 33.4 13.8 14.9 EA A,Se 138b 24 50 -25 0.2 14.0 14.8 E? P,La 141 25 15 -21 51.5 14.3 16.2 M M5: V2573 * 142a 25 24 -24 51.9 13.3 16.5 M M7 IK Sgr 142b 25 28 -24 51.9 13.8 14.1 M5 P,H 143 25 36 -26 22.8 14.1 [15.5 SRa M2: V2576 144a 25 40 -25 17.0 14.1 15.5 RR P,J 145a 25 47 -23 31.9 14.5 16.0 M M: V2578 * 146a 25 50 -24 25.0 13.5 14.1 M5: P,H 145b 25 51 -23 33.6 14.9 16.0 A,H * 144b 25 53 -25 17.6 11.8 15.9: M M9 IM Sgr 147 25 54 -25 6.5 14.1 15.2 P,La * 146b 25 59 -24 27.0 13.4 14.1 M: P,H 148 26 0 -23 58.8 13.9 15.3 RR V2580 149 26 1 -23 27.0 13.9 14.4 A,Di 150a 26 11 -22 7.2 14.0 16.4 M? M9 Hi * 152a 26 22 -23 20.5 14.1 [16.5 M M4 V1680 151 26 26 -22 37.0 15.0 15.5 A,H 152b 26 31 -23 18.6 13.9 14.9 Ib? M7 V2363 150b 26 37 -22 10.9 14.1 14.7 M6 Do,H 153 26 51 -26 26.7 12.9 13.5 M6 A,St 154a 26 54 -25 15.8 14.2 15.9 RR V2584 154b 27 5 -25 10.4 13.3 15.9 M M7 V1684 155 27 6 -23 9.0 11.2 11.8 M5 Z 156 27 16 -23 42.0 12.4 12.9 A,Z * 157 27 22 -22 20.2 14.7 16.3 RR? A,Sw 158 27 22 -21 52.6 15.1 [16.0 M M: V2585 159a 27 25 -22 56.1 14.4 15.5 A,Ap * 159b 27 32 -22 52.7 14.7 15.5 M A 160 27 32 -23 21.9 14.3 [16.0 M M5 V2586 161a 27 36 -25 8.5 13.8 14.3 M6 H 162 27 42 -23 49.0 13.9 14.6 I? M6 A,Bo * 163 27 43 -24 32.8 14.2 14.8 E? P,Gr * 164 27 46 -26 59.8 13.3 13.8 A,Se 165 27 51 -22 43.4 12.5 13.2 Pd A,Z * 161b 27 51 -25 10.2 14.1 [16.5 M V1686 166 27 59 -21 2.4 14.3 16.4 M M9: V2588 167 28 1 -23 37.0 14.1 14.9 I? M7 A,Bo * 168 28 2 -24 29.9 12.7 13.7 Ib M7 V2364 169 28 4 -23 24.2 14.7 16.0 I? A,H * 170b 28 10 -24 34.0 14.6 15.5 M7 P * 171 28 25 -23 6.1 14.5 15.7 RV V2589 172a 28 36 -22 0.6 14.7 16: M M6: V2365 172b 28 41 -22 1.6 14.7 15.6 RR V2366 173a 28 45 -23 57.6 12.9 14.2 SRb M7 V2367 174 28 49 -25 23.0 14.2 15.0 RR? Di 175 28 53 -23 43.8 14.2 14.8 M5 H 176 28 57 -25 7.4 14.5 16.2 RR? P 173b 28 58 -23 55.6 13.7 14.8 RR AJ 69 * 177 28 59 -21 38.7 14.9 [15.9 M V2591 178 29 8 -21 24.7 15.7 [16.4 M M7 V2368 179 29 15 -23 29.4 13.7 14.7 I? M2 A,Se 181a 29 21 -23 52.2 14.8 [16.5 SRa M6: V2007 * 180 29 24 -22 27.5 15.0 16.4 M M9 V2369 181b 29 24 -23 50.0 13.6 14.3 RRc V2592 182 29 25 -20 58.8 12.0 12.6 M6 B 183 29 38 -24 35.0 14.2 14.9 short? H 184a 29 58 -22 42.4 14.6 15.2 A,H 184b 30 2 -22 44.3 14.5 16.3 M V1698 185 30 2 -24 10.7 12.3 13.1 I? M: Z,Au,H 186 30 2 -25 12.0 14.2 14.8: M2 P,Gr 187a 30 9 -23 52.0 13.3 14.2 RR H,Au * 188 30 14 -20 48.6 12.8 14.8 SRb? M5 V2370 189 30 21 -21 36.4 13.8 15.6 M0 De 187b 30 24 -23 45.8 14.0 14.6 H,Au 190 30 33 -22 52.0 14.8 16.1 M M6: V2598 * 191 30 33 -24 3.3 12.0 13.0: H,Z,Au * 192 30 48 -22 13.9 13.2 14.1 M6 A,H 193 30 50 -22 20.6 14.8 15.6 RR? Sa * 194a 30 46 -26 56.9 13.4 14.3 H 194b 30 52 -26 57.4 13.4 14.2 M3 A,H 195 31 11 -24 47.2 13.9 14.9 Ib? M8 P,Gr 196 31 11 -25 24.2 13.4 14.3 A,H 197 31 19 -21 34.2 14.3 15.6 SR M3 V2600 198 31 34 -22 39.0 14.8 16.2 I? A,He 199 31 35 -22 17.6 14.4 16.2 M M7 V2372 200 31 54 -27 46.2 13.8 15.1 RR V2374 201 31 55 -22 5.7 14.5: 15.5 A.He * 202 31 59 -22 46.7 14.3 15.3 M6e V2601 * 203 32 14 -25 38.2 13.0 13.9 SR M6 V2376 204 32 16 -27 47.0 11.8 12.6 RR? Ro 205 32 18 -21 29.7 14.7 16.0 I? M2 A,We 206 32 41 -23 10.7 12.0 12.6 I? M5 AJ 70 207 32 41 -26 53.6 13.3 14.6 EA Cr 208 32 44 -22 46.2 13.8 15.4 RR? A,Ja 209 33 1 -19 56.4 12.8 14.5 M5 B 210 33 3 -20 33.4 14.6 15.5 A,De * 211 33 7 -21 14.2 12.5 15.2 RRab IBV 474 212 33 45 -24 3.1 13.2 13.8 A,Co 213 34 6 -24 36.6 11.7 12.5 EW A,Tw * 214 34 7 -21 28.1 13.5 14.5 EA V2606 215 34 7 -18 44.2 13.7 [15.5 M M9 V2378 216 34 38 -26 52.8 12.7 13.4 I? M5: Se 217 34 39 -25 19.6 13.2 13.8 M3 Al 218 34 45 -26 10.8 11.9 13.1 SRa M3 V2608 219 34 48 -24 49.3 13.6 14.2 Al 220 35 7 -23 22.2 15.0 16.3: RR? Ja,A 221 35 16 -25 49.2 13.8 14.9 I M5 V2380 222 35 36 -21 28.1 12.5 13.0 M3: B 223 36 9 -19 52.1 11.8 12.4 E? A,B * 224 36 43 -26 8.3 11.9 13.2 M2: Cr 225 36 56 -19 7.0 14.6 [16.1 UG V2383 226a 37 26 -21 18.8 13.9 16.2 M V1710 226b 37 30 -21 17.7 14.2 15.8 M AJ 72 227 37 33 -23 2.2 14.0 15.0 RR? Ja,A 228 38 2 -21 48.2 11.5 12.1 M: B 229 38 6 -23 0.3 14.2 15.4 E A,H 230 38 24 -20 22.2 14.2 15.5 RRab IBV 592 231 38 38 -24 7.6 14.0 14.8 short Sa 232a 38 42 -19 29.4 9.8 10.5 EA A0 YY Sgr * 232b 38 48 -19 29.0 14.8 16.0 I? A,Le # Observers A Jean Hales Andersen, Harvard 1955, 1958 Al Laura Alford, Randolph-Macon 1963 Ap Karen Alper, Case Western Reserve 1968 As Mary Ashman, Mt. Holyoke 1967 Au Doris Austin, Wellesley 1963 B Meredith Baldwin, Wellesley 1960 BC Jennifer Bagster-Collins, Mt. Holyoke 1959 Bo Linda Bothwell, Goucher 1966 Co Sharon Cox, Arizona 1961 Cr Sandra Crino, Wellesley 1961 De Linda Deery, Whitman 1968 Di Elizabeth Dippel, Mt. Holyoke 1963 Do Catherine Doremus, Indiana 1965 G Nahide Gokkaya, Wesleyan 1965 Gr Nancy Gregg, Colorado 1969 Gu Judith Guthrow, Randolph-Macon 1967 H D. Hoffleit He Susan Hess, St. Johns 1966 Hi Alice Hine, Vassar 1966 Ho Nancy Houk, Michigan 1962 J Jean Jackman, Vassar 1968 Ja Judith Jacobs, Smith 1964 Jo Lorella Jones, Radcliffe 1962 Ki Bonnie Kime, Wellesley 1964 Ku Andrea Kundsin, Wellesley 1957 L Gretchen Luft, Mt. Holyoke 1961 La Joann Lawless, Wellesley 1969 Le Wendy Levins, Vassar 1967 P Zora Prochazka, Harvard 1955 R Diana Reeve, Wellesley 1963 Ro Judith Robinson, Vassar 1961 Sa Martha Safford, Wellesley 1962 Se Sandra Servaas, Wellesley 1967 St Ilona Strockis, Wellesley 1960 Sw Marilyn Swim, Pomona 1965 T Jane Turner, Wellesley 1965 Tw Marilyn Twomey, Wellesley 1968 vS Gunilla von Schwerin, Harvard 1955 W Jean Warren, Swarthmore 1965 We Diana Welch, Park College 1967 Wh Janice White, Whitman 1969 Wo Katharine Wood, Vassar 1966 Z Catherine Zastrow, Mt. Holyoke 1960 * Remarks c Indicates images affected by companion Var. No. 4 Indications of cycles of about one month 6 Three companions 13 Cycles about 60 days; resembles UU Her 16 Period about 10 days? 18 Usually blended with 15 mag. companion 19 Fuzzy blended images resolved on only a few plates 25 Blended with three companions one of which has M-type spectrum 35 Overlapping spectra 42 Only one deep minimum observed, J.D. 2426591.361 45 Period about 0.78 day? 54a An error in position in Astron. J., Vol. 71, p. 130, Var. No. 1, is carried over into I.B.V.S. No. 311, 1968, and the General Catalogue of Variable Stars: for 11 minutes of R.A. read 17 minutes 63b Near globular cluster M28 63c S.I. Bailey Var No. 8 in cluster M28; c.f. Ann. Harvard Coll. Obs. 38, Plate XI 66 Suspect companions 68a Blended images. One companion, seen only on J.D. 2424431, may be a 13 mag. asteroid 69 Only one maximum, J.D. 2425854 72 HD 169460, NGC6629, planetary neb. 73 16 mag. companion 76 Usually near maximum 77 Two companions 78 Period 13-15 days? 80 Blended images 83a Only 5 observed, widely separated maxima 85b Spectrum overlapped by M-type star 86 Has companion with M-type spectrum 90 Light curve resembles R Cor Bor but with small amplitude 93 Blended images 94b Probably short period. Double images resolved on only 33 Bruce plates; preceding of two stars; companion 15.6 mag. 99 15.7 mag. companion, spectral class M7 100 Blended with two companions 103 Companion rarely resolved 105a Images blended except on Harvard Bruce plates 110 Conspicuous change in spectrum 112 Flanked by red stars 116c Probable RR Lyrae type. Blended images resolved only on Harvard Bruce plates 116d Magnitudes refer to blended images. The variable may be the fainter component, about 14.7 mag. 117c The variable is a faint star closely following the 12.5 mag. star marked on the chart. Seldom resolved. 119 At minimum a 16 mag. companion revealed. Variable is N of close pair. 120 Normally at maximum. Part of the observations indicate period of 53 days. 127 Overlapping spectra 131a 15.8 mag. companion rarely resolved 131b Variable is faint star N of brighter star with early M-type spectrum. 134b Appears to be RR Lyr type; if so, M2 may refer to overlapping spectrum. 137a Near cluster NGC 6642 137b Near cluster NGC 6642 141 Overlapping spectra 145a 1' N of NGC 6642. Companion 145b S of cluster NGC 6642. Estimates useful only on Harvard Bruce plates, on which companion is resolved. 147 Short period? Affected by companion on all but Bruce plates 150a Only three maxima observed: J.D. 2423948-9, 24765, 26577-594. Except on Bruce plates generally blended with nearby brighter star to S. 156 Suspect companion 159a 15.4 mag. companion, resolved on 66 Harvard Bruce plates. Only one well defined maximum, J.D. 2426557-569. 162 Probable companion. Amplitude small, but good correlation between the observers 163 Same as 170a 165 HD 171131, IC 4732, planetary nebula. 167 Small amplitude but good correlation between observers 169 Appears to be slowly varying 170a Same as 163. 170b Preceding variable on chart, 170a, is same as No. 163. 173b Member of globular cluster M22 181a Probable member of M22 187a H.S. Hogg Var. No. 15, Pub. David Dunlap Obs., Vol. 1, 297, 1944. Companion appears to have M type spectrum 190 15.8 mag. companion rarely resolved except on Bruce plates 191 Companion. Very bright object in lower left corner of chart represents globular cluster M22 193 Blended with 15 mag. companion 201 15 mag. companion rarely resolved 202 MH_alpha 208-51. Preceding of pair separated by 0.'3. 210 Usually blended image of two stars; var. is the Sf 213 Provisional period by Marilyn Twomey, 0.364913 day. A spectral class, M2, found by Miss Houk presumably refers to a close preceding unresolved companion seen on the red Palomar charts of this region but not on the blue. 223 Variable Suspect No. 4299. 232a Not examined in this survey: too bright [FIGURE 3] [FIGURE 4] [FIGURE 5] [FIGURE 6] [FIGURE 7] [FIGURE 8] [FIGURE 9] [FIGURE 10] [FIGURE 11] [FIGURE 12]