ACTA ASTRONOMICA Vol. 43 (1993) pp. 209±234
Extinction Law Survey Based on Near IR Photometry of OB Stars
by W. Wegner
Pedagogical University, Institute of Mathematics, Chodkiewicza 30, 85-064 Bydgoszcz, Poland
Received June 21, 1993
ABSTRACT
The paper presents an extensive survey of interstellar extinction curves derived from the near IR photometric measurements of early type stars belonging to our Galaxy. This survey is more extensive
and deeper than any other one, based on spectral data. The IR magnitudes of about 500 O and B type
(B V ) stars with E 0 05 were selected from literature. The IR color excesses are determined with the aid of "arti®cial standards". The results indicate that the extinction law changes from place
to place. The mean galactic extinction curve in the near IR is very similar in different directions and
= changes very little from the value R 3 10 0 05 obtained in this paper. Key words: extinction ± Infrared: stars
1. Introduction
The interstellar extinction is commonly believed to be caused by grains of interstellar dust. Their physical and geometrical properties are thus responsible for the wavelength dependence of the interstellar extinction (the extinction law or curve). Unfortunately, this curve is typically rather featureless (Savage and Mathis 1979) and thus the identi®cation of many, possibly different, grain parameters (chemical composition, sizes, shapes, crystalline structure etc.) is very dif®cult. Possible differences between extinction curves originating in different clouds may be very useful as probes of the physical conditions inside interstellar dark nebula. It is now rather well known that absorption spectra of single interstellar clouds (including extinction curves) differ very substantially (see e.g.,Kreøowski 1989 for review). The problem how the extinction law depends on galactic coordinates has be- came especially important since the ®rst UV spectra were obtained from IUE, ANS and TD-1 (Bless and Savage 1972, van Duinen et al. 1975, Jamar et al. 1976, Wesselius et al. 1982) and when ®rst near infrared observations were available 210 A. A.
(Johnson 1966, Hackwell and Gehrz 1974, Wiemer 1974, Schulz and Wiemer 1975, Kuriliene and Straizis 1977, Whittet and van Breda 1980, Koornneef 1983, The et al. 1986, Straizis 1987). A great majority of observationally determined extinction curves (see Aiello et al. 1988, Fitzpatrick and Massa 1990) concerns,however, relatively distant, heavily reddened objects. Such objects are very likely to be obscured by several interstellar clouds situated along the same line of sight, differing in their physical parameters and/or dust content (Kreøowski and Wegner 1989, Papaj, Wegner and Kreøowski 1991). Theextinctioncurvesderivedfromtheirspectraare ill-de®ned averages over all observed clouds and therefore ± useless as a source of information concerning physical parameters of dust particles contained in any one of them. The same concerns several "mean extinction curves" (Savage and Mathis 1979, Seaton 1979) averaged usually over the available samples ± they cannot be used to determine
structural details of interstellar grains.
With an increasing number of observations in the near infrared (0 71 5 m) of objects highly obscured by interstellar extinction, a precise determination of the reddening law is important, particularly for observations ofdark clouds. Mostwork in the past has been tied to observations in the visible (Johnson 1968, Hackwell
and Gehrz 1974) with correspondingly smaller reddening longward of 1 m than encountered for sources undetectable at visible wavelengths. Becklin et al. (1978a)
determined the reddening law longward of 1 m but they concentrate on wave-
lengths longer than 1.65 m and have a limited number of J ®lter measurements. The majority of determinations of interstellar extinction in near the IR ranges were calculated from a few sources of infrared radiation (Jones and Hyland 1980)
and for several IR passbands only. For Sco and for a few stars in the galactic center Rieke and Lebofsky (1985) obtained the "universal" extinction law from
measurements between 1 and 13 m. These authors received the mean value
(K V ) E (B V ) of R deduced from the diagram E vs. , very similar to other determinations obtained in various directions of galactic longitude: Whittet and van Breda (1980), (except the region in Orion and Sco-Oph dark cloud), Smyth and Nandy (1978), Sneden etal. (1978), Wiemer(1974). In thepapers of Kreøowskiand Wegner(1989), Wegner, Papaj and Kreøowski (1990),Wegner, Papaj and Kreøowski (1993) the authors reported different conclusions regarding interstellar extinction derived from spectra of "normal" OB stars and from stars OB with emission lines (in particular a part of Oe, Be stars with very great value of rotational velocities): the extinction law varies from place to place.
The method of dereddening with the aid of "arti®cial standards" adopted in this
(B V ) work allowed to investigate stars with color excesses E 0 05. This fact, as well as using a sample of OB stars much bigger than in other papers previously publishedon IR extinction, may help in the future discussionon physical conditions of dust in interstellar or circumstellar clouds. Vol. 43 211
2. Reduction of Data and Results
This paper is based on UBVRIJHKLM ± magnitudes of about 700 O and B type stars of luminosity class I±II, III and IV±V obtained from literature. The main sources are: the catalogue of infrared photometry of southern early type stars containing 229 stars (Whittet and van Breda 1980) and being a part of the catalogue of infrared observations (Gezari et al. 1984) of nearly 500 OB stars, a
catalogue of photometric data of 259 stars from 0.15 to 4.8 m (based in part on observations collected at the European Southern Observatory, La Silla, Chile ± The et al. 1986), 55 Be stars were taken from catalogue of Ashok et al. (1984). The
Johnson VRI data are taken from published catalogues by Johnson (1966) and by Fernie (1983). The accuracy of these data is of the order of 0 01. The Cousins red VRI measurements were transformed to Johnson`s revised photometric system
with the aid of the formulae
(Johnson ) = R (Cousins ) ( ) r =
R 0 988 0 002 0 02 ; 0 998
(Johnson ) = I (Cousins ) ( ) r = I 0 990 0 007 0 02 ; 0 995
where r means the respective value of the correlation coef®cient. The accuracies (in parentheses) give the standard deviations of the mean values of the differences
(Johnson) ± (Cousins). The effective wavelengths of R and I are 0.71 and 0.97 m respectively. We have utilized 93 commonly observed stars. Table 1 presents the distribution ofoursample ofstars according to their spectral type (O5 ± B9.5) and luminosity class (I±II, III, IV±V). There are 349 "normal" OB stars and 151 stars with emission lines. Fig. 1 shows the distribution of stars included into this survey. The "normal" OB stars are presented as circles, the stars with emission lines as dots. As one can see the stars are fairly uniformly
distributed along the Milky Way. Most of the infrared photometry is available in L K and bands. For all stars of our sample color-color diagrams have been formed in different two-color combinations but for different luminosity classes separately. Altogether 63 diagrams have been examined. They are clearly linear after a few stars signi®cantly deviating from the linear relations were eliminated. In mostcases
these stars are variable in one or several bands, or peculiar for their spectral and
K V )
luminosity class. For illustration, the most used two-color relations ( vs.
L V ) ( for three luminosity classes (I±II, III, IV±V) are shown in Figs. 2, 3, 4. They also contain 49 stars with emission lines except those deviating from linear relations, known mostly as variables in one or several infrared bands (see Feinstein 1975, Feinstein and Marraco 1981), or as extreme Be stars with infrared excesses. For some O stars and B8 and B9 stars no luminosity class assignment was found in literature. They have been assigned to the best ®tting two-color diagrams. All JHKL(M) measurements were reduced to the Glass (1974) JHKL photometric 212 A. A.
Table1 The distribution of the OB stars according to spectral type and luminosity
Sp/L I±II III IV±V Uncertain O5 2 2 7 6 O6 7 6 15 11 O7 4 10 16 13 O8 13 6 24 17 O9 15 10 21 1 B0 35 19 19 1 B1 23 2 24 0 B1.5 5 3 9 1 B2 12 4 44 5 B2.5 2 0 9 0 B3 9 7 22 6 B4 2 1 3 0 B5 5 2 8 4 B6 4 0 3 2 B7 3 0 6 3 B8 13 0 16 8 B9 8 3 17 9 Total 162 75 263 87
Fig. 1. Distribution of the stars, considered in this paper in the galactic coordinates. Dots ± stars with emission lines, circles ± normal OB stars. system, which is tied to the Johnson system, by comparing with standard stars of Glass (1974); transmission curves for the ®lters are presented by Glass (1973) and
Vol. 43 213
K V L V ) Fig. 2. ( diagram for supergiants I±II OB type stars. 12 stars with emission lines
Oe or Be are also located in this diagram.
K V L V ) Fig. 3. ( diagram for giants III OB type stars. 4 stars with emission lines Oe or Be
are also located in this diagram. M effective wavelengths are 1.25 ,1.65 ,2.2 and 3.5 m. The system is de®ned
by effective wavelength of 4.8 m. The Johnson UBV data are used. These data are obtained from a catalogue:
Blanco et al. (1970), Hof¯eit and Jaschek (1982), Nicolet (1978) (the accuracy of these data of the UBV magnitude is typically 0 01).
214 A. A.
K V L V ) Fig. 4. ( diagram for dwarfs IV±V OB type stars. 33 stars with emission lines Oe or Be are also located in this diagram.
Spectral classi®cations are taken from different sources: Hof¯eit and Jaschek (1982), Blanco et al. (1970), Kennedy and Buscombe (1974), Buscombe (1977, 1980, 1981, 1984). The existing intrinsic IR colors as a function of spectral type and luminosity class are presented in the papers of Johnson (1966), Lee (1970), Wiemer (1974), Kuriliene and Straizis (1977), Frogel et al. (1978), Whittet and van Breda (1980), Koornneef (1983) and Straizis (1987). A different method was adopted in these papers to obtain the intrinsic colors. The authors dereddened their target stars using an average reddening law derived from some slightly reddened stars. Kuriliene
and Straizis (1977) and Straizis (1987) used B supergiants, ®fty-®ve OB stars of
(B V ) luminosity classes II±V and 19 supergiants with low reddening E 0 3± WhittetandvanBreda(1980),used81BtypestarsofluminosityclassVand47stars OB type stars of luminosity class I were used by Wiemer 1974. As shown recently by Papaj, Wegner and Kreøowski (1990 PWK), such a procedure is very uncertain because slightly reddened stars are usually obscured by clouds characterized by extinction laws highly discrepant from any "mean law". This makes it dif®cult to
attach any realistic errors to these intrinsic colors. Moreover, the published intrinsic
V B `s differ from one determination to another (see the discussion of PWK). This fact creates large uncertainties among small color excesses which contributes substantially to the ®nal uncertainties of intrinsic colors. The determination of intrinsic IR colors applied in this paper is based on two- color diagrams and represents a certain system of determination of intrinsic UV Vol. 43 215 colors of OB stars (Papaj, Kreøowski, Wegner 1993). The method contains the following steps: ± stars showing any evidence of variability in observed colors were excluded;
± a careful selection of samples of the same Sp/L was performed;
V (B V ) ± two-color diagrams for these samples in the form ( ) vs. were plotted;
± a calculation of mean relation between the colors involved was made;
V (B V ) ± a calculation of intrinsic ( ) colors was performed by inserting the indices in these relations. The above mentioned two-color relations are always linear, hence the mean
relations between the color indices may be written as
V = a (B V ) + b ( )
1 b
where a and are the slope and intercept of the mean relation respectively.
V
When the intrinsic value of B is substituted into this formula the left hand
V )
side should equal the intrinsic ( color
V ) = a (B V ) + b ( )
( 0 0 2
B V ) which allows to calculate IR intrinsic colors when intrinsic ( `s are known. The precision of the latter determines the precision of the IR colors together with
the quality of the two-color relation. By subtracting Eq. (1) from Eq. (2) we obtain
V ) ( V ) = a [(B V ) (B V ) ] ( ) ( 0 0 3
which may be rewritten as
( V ) = a E (B V ) ( ) E 4
Thus the slope of a two-color relation determines the average normalized ex-
tinction curve for any sample of a given Sp/L types:
( V ) E (B V ) = a ( ) E 5
This procedure may be used to determine extinction curves only if we may assume that extinction law is the same towards all the stars under consideration as can be e.g.,in certain OB associations (Kreøowski and Strobel 1987). Another application of the method outlined aboveis the comparison of long distance average extinction curves, where the probability of any kind of cloud along a line of sight
is very similar and thus the extinction law (averaged over all intervening clouds)
B V ) does not differ much from one sightline to another. In this paper the ( 0 values obtained in the programme of determination of UV intrinsic colors (Papaj, Kreøowski, Wegner 1993) were used. For Sp/L types lacking in that paper the present author derived the intrinsic colors in a similar way as above (with a lower 216 A. A. precision however because of a smaller sample). These values were obtained with the aid of the method described above and with the assumption, that the extinction bump at 2200 AÊ should be absent in the "mean intrinsic" spectra. This fact and results of this paper allowed PWK to propose a new set of intrinsic and IR colors, slightly different from the older determinations. The additional question which is to be answered is whether intrinsic spectra of Be stars differ from those of "normal" B stars. The former objects are believed to be closely related to some diffuse matter in the form of e.g., disks. This matter causes probably an extinction different from that in diffuse interstellar clouds (Sitko et al. 1981, Schild 1983, Papaj, Wegner and Kreøowski 1991, Wegner, Papaj and Kreøowski 1990, Wegner, Papaj and Kreøowski 1993). It is thus of importance to decide whether intrinsic spectra of such stars are the same as those of B stars, being only affected by a "peculiar" extinction.
The scatter of points representing Be stars in our two-color diagrams is greater
B V ) than for normal B stars. However the intrinsic ( `s for these relations are identical. Thus we conclude that there is no signi®cant difference between intrinsic ¯ux distributions of normal B and Be stars ± the only problem is the correct
dereddening of the stars obscured by circumstellar shells.
(K V ) E (B V )
Fig. 5. Plot of E vs. for all stars in Table 5 except Oe and Be stars.
(K V ) E (B V ) Fig. 5 is a plot of E vs. for all stars in Table 5 except Oe
and Be stars. The best straight line, ®tted by least squares through 344 points has
R = R = E (K V ) E (B V ) K
a slope K 3 07 0 12 where 1 1 . For compar-
(K V ) E (B V ) ison, Fig. 6 is a plot of E vs. only for all Oe and Be stars
from Table 5. The best straight line, ®tted by least squares through 111 points has
R =
a slope K 3 18 0 13. The extinction curves have been derived from the photometric IR measurements using arti®cial standards given in Tables 2, 3 and 4. They are presented in Table 5 Vol. 43 217
Fig. 6. Same as in Fig. 5 for all Oe and Be stars from Table 5.
Table2
Intrinsic infrared color indices of supergiant OB type stars
B V ) (R V ) (I V ) (J V ) (H V ) (K V ) (L V ) (M V ) Sp ( 0 0 0 0 0 0 0 0
O5/O6 0.32 0.15 0.37 0.67 0.77 0.84 0.90 0.94
O7 0.31 0.14 0.36 0.65 0.75 0.81 0.86 0.92
O8 0.30 0.13 0.33 0.61 0.70 0.73 0.79 0.85
O9 0.27 0.12 0.30 0.58 0.68 0.72 0.78 0.79
O9.5 0.24 0.10 0.28 0.54 0.65 0.70 0.73 0.74
B0 0.22 0.09 0.24 0.49 0.59 0.62 0.66 0.67
B0.5 0.20 0.08 0.24 0.47 0.58 0.60 0.62 0.63
B1 0.19 0.08 0.23 0.46 0.55 0.58 0.60 0.61
B1.5 0.17 0.06 0.18 0.41 0.44 0.47 0.48 0.51
B2 0.16 0.06 0.16 0.40 0.43 0.46 0.47 0.48
B2.5 0.14 0.04 0.14 0.33 0.35 0.38 0.39 0.40
B3 0.13 0.03 0.12 0.27 0.34 0.35 0.36 0.37
B5 0.08 0.00 0.06 0.15 0.17 0.20 0.21 0.24
B6 0.06 0.01 0.04 0.10 0.12 0.13 0.14 0.17
B7 0.04 0.02 0.02 0.05 0.06 0.07 0.08 0.10
B8 0.03 0.03 0.00 0.01 0.04 0.05 0.06 0.09
B9 0.01 0.05 0.02 0.01 0.01 0.03 0.04 0.05 k
as the ratios of color excesses :
0
m V m E
V
( )
k = ( ) =
6
E (B V ) (B V )
V B 0
where:
(B V ) B V
± photoelectric color,
B V ) B V
( 0 ± intrinsic color from Tables 2, 3, 4,
m
± monochromatic magnitude of the target star at wavelength .
0
m ± normalized ¯ux at wavelength for arti®cial standard (from Tables 2, 3, 4). 218 A. A.
Table3
Intrinsic infrared color indices of giant OB type stars
B V ) (R V ) (I V ) (J V ) (H V ) (K V ) (L V ) (M V ) Sp ( 0 0 0 0 0 0 0 0
O5/O6 0.30 0.15 0.37 0.68 0.80 0.88 0.91 0.96
O7 0.29 0.15 0.36 0.66 0.77 0.85 0.87 0.93
O8 0.27 0.14 0.35 0.62 0.73 0.80 0.83 0.90
O9 0.26 0.13 0.31 0.59 0.69 0.77 0.79 0.81
B0 0.23 0.11 0.27 0.51 0.60 0.69 0.75 0.76
B0.5 0.22 0.11 0.26 0.48 0.59 0.67 0.73 0.74
B1 0.21 0.10 0.26 0.46 0.55 0.65 0.70 0.71
B1.5 0.20 0.09 0.25 0.43 0.50 0.60 0.65 0.67
B2 0.19 0.08 0.24 0.38 0.46 0.56 0.62 0.64
B3 0.16 0.06 0.18 0.34 0.40 0.46 0.51 0.53
B5 0.15 0.06 0.18 0.31 0.35 0.41 0.44 0.46
B6 0.13 0.05 0.16 0.28 0.31 0.35 0.38 0.40
B7 0.12 0.04 0.15 0.24 0.26 0.30 0.31 0.33
B8 0.10 0.02 0.11 0.19 0.20 0.22 0.23 0.24
B9 0.07 0.00 0.05 0.07 0.08 0.09 0.10 0.10
Table4
Intrinsic infrared color indices of dwarf OB type stars
B V ) (R V ) (I V ) (J V ) (H V ) (K V ) (L V ) (M V ) Sp ( 0 0 0 0 0 0 0 0
O5/O6 0.30 0.17 0.43 0.73 0.81 0.89 0.92 1.02
O7 0.29 0.16 0.42 0.71 0.79 0.86 0.88 0.97
O8 0.285 0.15 0.41 0.68 0.77 0.84 0.85 0.92
O9 0.28 0.15 0.40 0.61 0.72 0.79 0.82 0.91
O9.5 0.27 0.14 0.39 0.60 0.71 0.77 0.80 0.88
B0 0.26 0.14 0.37 0.58 0.69 0.76 0.78 0.86
B0.5 0.24 0.13 0.34 0.53 0.63 0.69 0.72 0.79
B1 0.23 0.12 0.33 0.51 0.60 0.66 0.71 0.76
B1.5 0.22 0.11 0.31 0.50 0.56 0.62 0.64 0.70
B2 0.21 0.10 0.29 0.48 0.52 0.59 0.63 0.68
B2.5 0.195 0.09 0.27 0.43 0.48 0.54 0.56 0.62
B3 0.18 0.08 0.24 0.39 0.45 0.49 0.53 0.58
B4 0.16 0.07 0.21 0.35 0.40 0.45 0.48 0.52
B5 0.15 0.06 0.19 0.33 0.39 0.42 0.45 0.47
B6 0.14 0.05 0.18 0.31 0.35 0.39 0.40 0.43
B7 0.13 0.04 0.16 0.28 0.32 0.35 0.36 0.38
B8 0.11 0.03 0.12 0.24 0.26 0.29 0.30 0.32
B9 0.07 0.01 0.08 0.15 0.16 0.17 0.18 0.19 Vol. 43 219
Table5
E
V
k =
Ratios of consecutive excesses
E
B V
E k k k k k k k
V R I J H K L M
HD Sp/L B
108O6e 0.50 ...... 2.74 3.06 : 4.02 : 4.66
1544B0.5III 0.38 ...... 2.71 2.71 ...
2623 B9IIIn 0.08 ...... 1.25 ... 3.38 ......
2905 B1Iae 0.33 0.67 1.30 1.91 2.85 2.48 2.58 3.18
3901 B2IV 0.10 0.80 1.50 2.60 ... 2.60 4.00 ...
4180 B5IIIe 0.08 : 1.88 : 2.75 2.38 2.25 2.50 3.13 : 7.75
5394 B0IVe 0.11 2.64 4.00 6.82 8.73 11.36 13.9 15.1
6140B2IbIIe 0.61 ...... 2.70 3.08 ......
7636B1.5e 0.36 ...... 2.39 3.28 ......
7902O6Ib 0.72 ...... 2.74 2.97 ...
10516 B2Vep 0.17 1.59 2.82 4.24 6.00 7.71 11.0 13.6
12302 B1Vpe 0.48 ...... 2.92 3.35 ......
13669B2e :0.56 ...... : 0.50 : 0.75 ......
13854 B1Iabe 0.47 ...... 3.06 3.30 3.00
14134 B3Ia 0.60 ...... 2.02 ... 2.63 2.97 3.10
14143 B2Ia 0.68 ...... 2.18 ... 2.71 2.94 3.25
14322 B8Ib 0.35 0.89 1.66 2.00 ... 2.71 2.74 ...
14422 B1Ve 0.72 ...... 1.92 2.25 ......
14542B8Ia 0.65 ...... 2.77 2.95 2.76
14605 B0.5Ve 0.51 ...... 2.94 3.63 3.82 ...
14818 B2Iae 0.47 0.83 1.45 2.00 2.57 2.62 2.86 3.26
14947 O6e 0.77 ...... 2.38 3.27 ...
14956 B2Ia 0.88 0.84 1.52 ...... 2.52 2.78 ...
15497 B6Ia 0.84 0.86 1.63 ...... 2.63 2.86 2.94
15570 O5f 1.02 ...... 2.18 ... 2.45 ......
16779B2Ibe 0.90 ...... 2.53 2.67 ...
17145 B8Ia 0.85 0.88 1.65 ...... 2.71 2.84 ...
17520 O8V 0.605 ...... 2.15 ... 2.64 ......
17603 O8.5If 0.93 ...... 2.56 2.91 ...
18552 B8Vne 0.05 ...... 1.80 3.00 2.20 ......
19356 B8V 0.06 1.17 2.17 3.33 ... 2.83 : 7.00 : 9.83
19820 O8 0.795 ...... 2.50 2.40 ...
20336 B2.5Ven 0.045 1.11 2.22 5.33 6.44 8.44 ......
21071 B7V 0.05 ...... 1.40 2.40 1.80 ......
21212 B2Ve 0.80 ...... 2.79 3.23 3.78 3.76
21291 B9Ia 0.42 0.81 1.74 2.31 ... 2.93 3.17 3.40
21483 B3III 0.52 ...... 2.13 2.42 2.62 2.77 ...
21943 B8 0.08 ...... 2.63 3.00 3.13 2.88 ...
23016 B9Vne 0.06 ...... 1.33 1.67 ......
23060 B2Vp 0.31 ...... 2.10 2.32 2.55 2.71 ...
23180 B1III 0.26 0.85 1.46 ...... 2.62 2.73 2.96
23288 B7IV 0.09 ...... 3.22 ... 2.33 3.33 ...
23324 B8V 0.04 ...... 2.75 ... : 1.50 2.75 ...
23432 B8V 0.07 ...... 2.86 ... 3.29 3.29 ...
23480 B6IVe 0.08 ...... 4.13 ... 6.38 7.63 6.88 23753 B8V 0.04 ...... 2.75 ... : 1.75 ...... 220 A. A.
Table5
continued
E k k k k k k k
V R I J H K L M HD Sp/L B
23793B3V 0.05 ...... 3.20 ......
23802 B7 0.30 ...... 2.27 2.60 2.80 3.07 ...
24398 B1Ib 0.31 0.71 1.48 2.13 2.42 2.58 2.61 2.90
24600 B8 0.35 ...... 2.40 2.77 3.00 2.29 ...
24736 B8 0.23 ...... 2.26 2.43 2.65 2.61 ...
24912 O7e 0.30 1.07 1.90 2.63 ... 2.97 3.23 : 5.33
25558B3V 0.10 ...... 2.80 ......
26571B9IIIp 0.26 ...... 2.35 3.58 : 2.46
29866 B8IVne 0.16 ...... 2.25 2.94 3.06 ......
30836 B2III 0.04 1.00 1.00 0.25 0.50 3.25 2.75 ...
32343 B2.5Ve 0.115 ...... 2.70 3.74 5.39 ......
32990B2V 0.27 ...... 3.04 ......
33232B3e :0.25 ...... 3.36 4.04 ......
33461 B2Ve 0.48 ...... 5.13 5.63 6.54 ...
34078 O9.5Vep 0.49 ...... 2.88 3.02 2.94 3.12
34748 B1.5Vn 0.11 1.00 1.55 1.64 ... 2.00 3.64 ...
34989 B1V 0.10 1.30 2.10 1.60 3.00 1.80 2.10 ...
35039 B2IVV 0.04 1.00 1.25 3.00 ... 2.50 3.50 ...
35079 B3V 0.15 0.67 1.33 2.07 ... 2.53 3.87 ...
35149 B1V 0.08 0.88 1.25 1.88 ... : 1.25 : 0.63 ...
35411 B1V+B2e 0.04 0.50 1.00 1.25 ......
35502 B5V 0.12 0.75 1.17 1.75 ... 2.00 3.83 ...
35673 B9V 0.07 0.71 1.43 2.14 ... 2.29 ......
35910 B6V 0.04 0.75 1.00 1.25 ... 4.25 ......
36351 B1.5V 0.04 1.75 1.25 1.00 1.75 2.25 3.75 ...
36605 B9 0.15 ...... 2.73 3.13 3.33 2.87 ...
36619 O7 0.49 0.45 1.06 2.08 2.33 2.43 2.76 ...
36629 B2V 0.23 ...... 2.91 3.04 3.52 3.91 : 5.78
36646 B4Vn :0.07 ...... : 0.14 ... : 0.43 ......
36695 B1V 0.05 ...... 1.00 ... 1.80 ......
36781 B9 0.10 0.90 1.70 1.60 2.00 : 1.10 2.50 ...
36811 B9 0.25 ...... 2.08 2.68 2.68 ......
36819B2.5IV 0.105 ...... 3.33 ......
36822 B0III 0.07 : 1.43 1.86 1.57 ... : 1.71 2.71 ...
36826 B9 0.07 ...... 2.86 3.43 3.29 3.86 ...
36861 O8e 0.095 +0.11 0.84 2.11 ... 2.21 : 0.84 4.21
37017 B1.5V 0.09 ...... 1.89 3.11 2.44 : 2.00 : 5.33
37020C O7 0.35 ...... 4.89 ... 6.40 7.69 ...
37022 O6 0.38 ...... 3.24 ... : 4.26 4.18 3.89
37040 B2.5IV 0.055 ...... : 0.91 2.91 : 2.18 : 2.00 : 12.0
37041 O9.5Vep 0.18 ...... 10.94 11.83 12.44 14.2 14.8
37042 B0.5V 0.12 ...... 4.42 4.00 6.33 9.08 ...
37061 B1V 0.49 ...... 3.29 3.55 3.88 4.06 4.12
37140 B9 0.16 1.13 1.94 3.06 ... 3.69 : 6.56 ...
37356 B2IVV 0.17 0.94 ... 2.41 3.00 2.76 2.76 4.18
37519 B9.5IIIIV :0.08 1.88 1.88 3.38 ... 1.75 ...... Vol. 43 221
Table5
continued
E k k k k k k k
V R I J H K L M
HD Sp/L B
37776 B2V :0.07 ...... 1.00 1.57 1.14 ... : 8.71
37903 B1.5V 0.32 0.94 2.00 3.03 3.47 3.66 3.22 ...
38087 B3 :0.31 1.00 2.06 3.55 4.68 5.10 4.94 ...
38165 B9 0.31 0.90 1.77 2.35 2.77 2.90 2.94 ...
38563A B5 0.77 1.03 1.96 2.27 3.39 3.00 4.29 ...
38708 B3e 0.19 ...... 3.32 3.63 ...... 39680O6e :0.34 ...... 6.21 7.82 ...
39746B1II 0.41 ...... 2.88 ......
40111 B0.5II 0.14 1.00 1.36 ...... 2.29 3.00 ...
41117 B2Iave 0.44 0.84 1.57 2.18 ... 2.73 3.02 3.50
41335 B2Ven 0.15 1.40 2.87 4.67 5.27 6.80 9.87 11.1
41398B2Ib 0.48 ...... 2.90 ......
41690B1V 0.44 ...... 2.25 ......
42087B2.5Ibe 0.35 ...... 2.57 ......
42088O6 0.37 ...... 2.86 ......
42259 B0e 0.58 ...... 2.21 2.53 2.86 2.91 ...
43384 B3Ib 0.57 0.93 1.79 ...... 2.98 3.16 3.30
43818B0II 0.51 ...... 3.16 ......
44458 B1Vpe 0.21 1.81 3.00 4.48 5.19 6.38 8.57 10.4
44965B3II 0.44 ...... 2.95 ......
45314 O9e 0.43 ...... 2.44 3.56 ...
45626B7 0.18 ...... 3.22 : 4.50 ......
45677 B2IVe 0.24 ...... 0.54 7.21 14.67 25.1 29.7
45910 B2IIIe 0.51 1.12 2.53 ... 5.08 5.84 6.41 7.06
45995 B2V:nne 0.13 ...... 4.85 5.46 8.46 ......
46106 B0.5V 0.38 ...... 2.61 ... 3.16 4.08 ...
46149 O8V 0.445 ...... 2.18 ... 2.88 2.65 ...
46150 B2V 0.34 ...... 2.18 2.41 2.53 2.41 ...
46223 O5 0.53 ...... 2.36 2.66 2.87 3.85 ...
46380B2Ve 0.64 ...... 3.20 ......
46484 B1V 0.59 ...... 2.22 2.53 2.24 2.61 ...
46485 O7V 0.61 0.62 1.44 2.41 2.64 2.75 2.84 ...
46559B8Iab 0.64 ...... 2.55 ......
46573 O7 0.63 ...... 2.38 2.62 2.75 2.62 ...
46711B3II 1.00 ...... 2.78 ......
46867 B0.5IIIIV 0.44 ...... 2.82 ...... 46883B0.5V 0.64 ...... 2.72 2.86 ...
46966 O8V+O8f 0.245 ...... 2.82 ......
47032B0III 0.68 ...... 2.72 ......
47129 O7.5III 0.33 0.67 1.58 2.73 2.88 3.18 3.67 4.52
47240 B1Ib 0.33 ...... 2.61 2.94 3.09 3.00 ...
47382B0III 0.40 ...... 2.73 ......
47432 O9.5I 0.39 0.64 1.33 2.18 2.46 2.67 2.72 ...
47839 O7Ve 0.04 ...... 2.00 6.00 5.50 3.75 ...
48279 O8 0.435 ...... 3.06 ......
48434B0III 0.21 ...... 2.95 ...... 222 A. A.
Table5
continued
E k k k k k k k
V R I J H K L M HD Sp/L B
49977 B1.5Vne 0.42 ...... 3.81 ......
50064 B6Iae 0.83 ...... 2.53 2.96 3.25 3.42 3.63
52266 O9V 0.27 ...... 3.33 ......
52382B1Ib 0.40 ...... 2.75 ......
52721 B2e :0.27 ...... 2.85 3.04 3.89 4.67 5.89
53138 B3Iab 0.10 ...... : 0.80 : 1.20 : 0.40 : 1.70 ...
53367 B0IVe 0.70 ...... 2.60 3.10 3.53 4.36 : 5.06
53755B0.5V 0.19 ...... 2.32 ......
53974B0.5IV 0.29 ...... 2.83 2.93 3.45
53975 O8V 0.185 0.65 ...... 3.08 2.92 ......
54309 B2IVe 0.11 ...... 5.27 5.82 6.91 ......
54439B2III 0.23 ...... 2.57 ......
54662 O6.5V 0.33 0.64 1.33 2.15 2.39 2.61 2.70 2.91
55879B0III 0.05 ...... 3.40 ......
56624B3IIIe 0.51 ...... 2.84 3.35 ......
56847 B7Ibe 0.23 ...... 3.43 4.09 ......
57060 O7I 0.46 0.37 0.57 0.93 1.17 1.26 1.61 1.56
57061 O9Ib 0.13 ...... 2.31 2.69 2.85 3.38 ...
57150 B2V 0.11 1.73 3.00 2.91 4.36 6.55 11.3 13.4
57219 B2IVne 0.05 0.80 0.40 2.00 2.20 2.20 2.60 3.40
57682 O9V 0.09 ...... 2.89 3.33 3.56 : 2.00 ...
58131B2n 0.55 ...... 3.24 ......
58343 B2.5IVe 0.145 0.62 1.72 2.07 2.28 2.48 : 8.07 3.59
58978 B0IV:pe 0.13 ...... 1.65 8.54 9.38 ...
59075 B8I 0.37 ...... 1.92 2.43 2.70 3.03 ...
59094 B2Ve 0.36 ...... 3.19 3.86 4.75 5.53 ...
60325B1V 0.19 ...... 2.53 ......
60479 B0II 0.56 ...... 2.21 2.50 2.68 2.57 ...
60606 B3Vne 0.12 2.08 2.92 4.58 5.83 7.75 11.8 13.8
60855 B2Ve 0.09 ...... 3.22 2.78 2.78 3.44 : 7.33
61827 O8 0.905 ...... 2.17 2.45 2.70 2.87 ...
62150 O5 0.85 ...... 2.13 2.48 2.68 2.84 ...
63462 B0Vpe 0.21 1.29 2.29 3.71 4.33 5.57 7.43 8.48
63922 B0III 0.05 0.60 : 0.40 1.00 3.00 2.40 3.00 2.40 64760 B0.5Ib 0.06 1.00 1.67 ...... 65818B1V 0.06 ......
65873 B9.5Vn 0.05 ...... :+1.40 ... 4.00 ...
65875 B2.5Ve 0.125 0.48 1.36 0.80 5.84 6.64 6.96 6.72
66194 B2IVpne 0.12 ...... 2.50 2.67 3.08 : 4.50 : 5.83
66811 O5Iaf 0.06 0.50 : 0.50 2.00 3.83 3.83 5.50 5.67
68450 O9.5II 0.23 0.70 1.39 2.48 2.57 2.70 3.13 2.78
68980 B1.5IIIe 0.09 2.11 2.89 5.56 6.33 9.22 ......
69106 B0.5II 0.11 0.64 1.73 2.82 2.82 2.55 2.91 : 7.27
69464 O7e 0.60 ...... 2.72 3.05 3.38 3.45 ...
69882 B1III 0.52 ...... 2.27 2.60 2.87 2.98 ...
70011 B9.5V 0.04 ...... 2.25 3.25 : 0.75 3.75 ... Vol. 43 223
Table5
continued
E k k k k k k k
V R I J H K L M
HD Sp/L B
70930 B1V 0.08 1.00 2.00 2.38 ... 3.88 ......
71304 O9I 0.80 0.73 1.48 2.06 2.35 3.16 2.79 2.66
73882 O8.5V 0.685 0.72 1.61 2.61 2.86 3.05 3.18 3.01
74194 O8.5I 0.52 0.62 1.35 2.38 2.54 2.63 2.98 2.88
75211 O8II 0.71 0.58 1.25 2.14 2.41 2.55 2.76 2.72
75222 B0Iab 0.60 ...... 2.30 2.72 2.83 2.77 ...
75759 O9V 0.18 0.72 1.83 2.28 2.39 2.39 2.56 2.44
75860 B1.5Iae 0.90 ...... 2.59 2.94 3.20 3.33 ...
76534 B3Ve 0.31 ...... 1.81 2.10 2.65 : 4.42 ...
76556 O6III 0.71 0.63 1.41 2.38 2.65 2.86 2.90 2.90
76838 B3V 0.18 ...... 2.22 2.50 2.50 : 5.22 ...
76868 B6e 0.34 ...... 6.06 6.59 ......
76968 B0II 0.35 0.69 1.54 2.20 2.69 2.83 3.23 2.97
77581 B0.5Ib 0.70 0.91 1.51 2.13 2.50 2.67 2.76 ...
78785 B2II 0.68 ...... 2.29 2.53 2.65 2.59 ...
79186 B5Ia 0.31 0.94 1.84 2.23 ... 3.00 ......
80558 B6Iae 0.49 ...... 2.94 3.37 3.63 4.04 ...
83183 B5II 0.09 0.67 1.44 2.00 2.22 2.67 3.33 3.89
84567 B0.5IIIn 0.09 0.89 1.89 2.44 2.89 3.33 : 4.67 ...
86612 B4Ve 0.06 0.67 1.17 ... 5.83 8.33 15.0 20.8
88661 B2IVpne 0.13 0.85 1.77 3.85 4.92 6.62 9.85 11.3
89137 O9.5III 0.23 0.52 1.26 1.48 1.83 2.22 2.96 ...
89884B5e :0.05 ...... 5.40 6.60 ......
90706 B3I 0.60 ...... 2.27 2.67 2.87 2.63 ...
91120 B9Vne 0.05 ...... 5.00 3.80 6.00 ...
91316 B1Ib 0.05 0.60 : 0.40 2.60 3.60 2.20 3.60 5.20
91619 B7Iae 0.33 ...... 3.45 4.09 4.45 5.61 ...
93030 B0Vp 0.04 ...... 2.00 4.50 ... : 1.00 : 1.75
93205 B3V 0.23 1.17 2.30 3.48 3.83 4.04 4.04 3.70
93222 O7III 0.34 0.79 1.88 3.35 4.06 4.53 4.62 ...
93250 O5 0.48 ...... 2.73 3.04 3.29 3.42 3.23
93540 B6Ve 0.04 0.75 3.00 2.00 3.75 2.75 4.00 ...
93843 O5III 0.25 0.76 1.80 2.36 3.04 3.52 3.76 ...
94367 B9Ia 0.10 ...... 4.10 5.30 6.10 7.20 ...
94878 B0Ve 0.93 0.78 1.54 2.60 3.57 4.76 6.32 7.02
94963 O6.5III 0.22 0.73 1.64 2.27 2.64 3.09 3.41 ...
95880 B8 0.45 ...... 2.24 2.60 2.89 3.18 ...
96042 O9.5V 0.45 : 0.22 1.11 2.09 2.49 2.84 3.00 ...
96446 B2Vne 0.05 ...... 2.60 4.00 2.00 2.80 : 10.4
96622 O9.5IV 0.39 0.74 1.74 2.31 2.74 3.05 3.56 ...
96917 O8.5I 0.37 0.65 1.59 1.89 2.51 2.49 2.68 ...
96919 B9Ia :0.17 ...... 3.76 4.65 5.29 5.82 ...
97253 O5III 0.15 1.93 4.27 6.60 7.87 8.47 9.00 ...
97319 O7.5III 0.48 0.75 1.69 2.50 2.75 2.88 3.65 ...
97434 O8 0.45 0.58 1.38 2.20 2.42 2.49 3.04 ... 97670 B1.5V 0.12 ...... 2.25 3.25 ...... 224 A. A.
Table5
continued
E k k k k k k k
V R I J H K L M
HD Sp/L B
97707 B2Ia 0.67 ...... 2.22 2.49 2.70 2.90 ...
97848 O7.5III 0.26 0.73 1.73 2.46 3.15 3.50 4.54 ...
97966 O6.5V 0.37 0.51 1.43 1.89 2.22 2.49 3.38 ...
98624 B1Vne 0.45 ...... 3.49 4.73 ......
99160 O9II 0.49 0.71 1.49 2.39 2.71 2.98 3.76 ...
99953 B2Ia 0.48 ...... 2.38 2.73 3.00 3.27 ...
100099 O9III 0.35 0.71 1.60 2.60 2.97 3.29 3.31 ...
101008 O9V 0.28 0.57 1.71 2.36 2.46 2.57 3.61 ...
101065 B5 :0.93 ...... 1.35 1.46 1.78 1.61 ...
101131 O6V 0.33 0.70 1.91 2.52 2.64 2.76 3.00 ...
101190 O6III 0.36 0.61 1.42 2.19 2.50 2.61 2.75 ...
101205 O7III 0.34 0.74 1.68 2.32 2.74 2.97 3.41 ...
101298 O6III 0.38 0.66 1.55 2.29 2.66 3.00 3.08 ...
101545 O9.5I 0.26 0.77 1.46 2.19 2.58 2.77 3.00 3.23
104901 B8IbII 0.21 ...... : 0.10 4.19 6.71 ...
105627 O8.5III 0.29 0.72 1.59 2.38 2.83 3.03 3.41 ...
106068 B8Ia Iab 0.32 ...... 2.47 2.91 3.22 3.50 ...
109399 B1Ib 0.20 ...... 2.65 3.05 3.05 : 2.40 ...
110432 B2pe :0.48 0.98 1.81 2.79 3.31 4.04 5.08 5.69
111124 B0 0.90 ...... 2.63 3.06 3.41 3.73 ...
111558 B8Ia 0.15 ...... 2.93 3.60 4.00 : 4.67 ...
112244 O8.5I 0.30 0.53 1.17 1.93 2.33 2.43 3.10 ...
112784 O9.5III 0.33 0.55 1.24 2.21 2.36 2.42 1.42 ...
113120 B1.5IIIne 0.25 ...... 1.16 1.52 2.12 3.08 3.72
113659 O9IV 0.33 0.61 1.48 1.82 2.24 2.27 2.45 ...
113904 B0Ia+WC5 0.20 ...... 2.45 3.45 3.95 ......
114213 B1Ib 1.10 ...... 2.44 2.80 3.00 3.15 ...
114737 O9IV 0.45 0.69 1.62 2.36 2.71 2.91 3.24 ...
114886 O9III 0.35 0.71 1.54 2.34 2.77 3.06 3.23 ...
115455 O7V 0.49 0.59 1.49 2.37 2.59 2.80 3.31 ...
115842 B0.5Iae 0.51 0.75 1.49 2.27 2.69 2.88 3.00 ...
116084 B2.5Ib 0.26 0.62 1.46 1.96 2.42 2.58 2.88 2.58
116119 B9I 0.72 ...... 2.46 2.82 3.04 3.14 ...
116852 O9III 0.18 0.61 1.44 : 0.27 1.11 1.88 1.56 ...
117797 O8f 0.80 0.60 1.38 2.24 2.59 2.75 3.03 ...
119159 B0.5III 0.14 0.79 1.64 1.93 2.43 2.50 2.86 : 4.36
120678 O8III 0.52 :+0.06 : 0.71 1.58 2.23 2.85 3.67 ...
120991 B2IIIe 0.12 +0.50 0.00 5.75 7.25 9.25 12.08 12.67
122879 B0Iae 0.34 ...... 2.47 2.88 3.06 3.21 ...
123056 O9.5V 0.43 0.60 1.44 1.98 2.40 2.47 2.44 ...
124314 O6.5 0.53 0.57 1.30 1.62 1.85 2.13 2.51 ...
124367 B4Vne 0.08 3.00 5.25 4.00 5.13 7.25 12.8 16.8
124471 B1.5III 0.14 ...... 2.07 2.14 2.50 2.14 ...
124979 O8.5 0.385 ...... 1.90 2.16 2.47 ......
125206 O9.5V 0.53 ...... 2.15 2.51 2.79 2.87 ...
125241 O8.5I 0.78 0.60 1.28 2.22 2.55 2.69 2.94 ... Vol. 43 225
Table5
continued
E k k k k k k k
V R I J H K L M
HD Sp/L B
125288 B6Ib 0.18 0.61 1.72 2.00 2.67 2.89 3.11 3.11
133518 B3III 0.06 ...... : 0.50 3.33 2.33 2.17 8.17
135160 B0.5Ve 0.16 0.75 1.81 1.88 2.44 2.44 2.69 : 2.00
135240 O7.5III 0.22 0.86 1.68 1.91 2.32 2.50 2.50 3.23
135591 O8IIIp 0.17 ...... 3.06 3.65 : 4.29 3.88 ...
140543 B0.5III 0.21 0.76 1.52 1.90 2.62 2.62 2.52 ...
142468 B0.5I,B2 0.81 ...... 2.12 2.46 2.63 2.81 ...
142983 B5IIIp 0.06 +0.83 0.33 9.50 8.00 11.83 17.0 23.83
142990 B5IV 0.06 ...... 2.67 3.83 1.83 2.50 2.17
143275 B0.5IV 0.12 0.67 1.33 2.25 3.00 2.75 2.50 4.00
144217 B1V 0.16 0.81 1.56 2.94 ... 3.19 3.69 ...
144470 B1V 0.19 0.89 1.58 2.47 ... 3.11 2.84 ...
144844 B9IVp 0.09 ... 1.89 3.44 3.88 3.78 ......
144900 O9V 1.04 ...... 2.26 2.52 2.68 2.88 ...
144969 B0.5Ia 1.14 ...... : 3.49 2.88 3.09 3.31 ...
145502 B3V 0.22 0.86 1.73 2.68 ... 3.32 3.59 ...
146706B9V 0.21 ...... 2.95 ......
147165 B2III+O9.5V 0.32 0.91 1.75 2.50 2.94 3.31 3.47 : 4.88
147196B8V 0.29 ...... 3.55 ......
147384 B9.5V 0.48 ...... 2.77 3.21 3.38 3.50 ...
147648 B8V 0.89 0.61 1.80 2.62 3.08 3.34 3.53 ...
147701 B5V 0.72 ...... 4.15 4.63 4.94 5.19 ...
147888 B3V 0.50 ...... 2.76 3.18 3.48 3.64 ...
147889 B2V 1.07 ...... 2.86 3.37 3.71 3.89 ...
147933/4 B2IVB2V 0.45 1.89 3.00 3.96 4.44 4.73 4.63 ...
148184 B2IVpe 0.49 1.12 2.00 2.86 3.55 4.16 4.78 5.00
148379 B1.5Iape 0.73 0.86 1.67 2.40 2.71 2.95 3.12 ...
148579 B9V 0.35 ...... 2.94 3.49 3.97 4.37 ...
148605 B2V 0.10 0.40 0.90 3.00 2.60 3.30 2.20 ...
148688 B1Iae 0.52 0.94 1.81 2.75 3.17 3.46 3.65 ...
148937 O6f 0.66 ...... 2.27 2.55 2.82 3.14 ...
149038 B0Ia 0.27 0.96 1.93 2.63 3.07 3.26 3.67 3.22
149363 B0.5III 0.24 0.75 1.54 1.92 2.33 2.71 2.21 ...
149367B9 0.22 ...... 3.05 ......
149757 O9.5Vn 0.29 0.83 1.55 1.97 2.24 2.41 2.69 3.00
149827B9 :0.29 ...... 6.21 ......
150136A O5 :0.49 ...... 5.35 5.61 5.84 ...
150168 B1Iab Ib 0.14 0.93 : 2.43 1.86 2.50 3.43 3.57 3.93
150898 B0.5Ia 0.12 ...... 3.08 3.50 3.42 3.58 ...
151003 O9II 0.44 0.73 1.48 2.59 2.73 2.82 2.93 3.36
151213 B0IV 0.55 ...... 2.31 2.64 2.84 2.78 ...
151346 B7p 0.54 ...... 2.93 3.39 3.63 3.63 ...
151515 O7III 0.45 0.64 1.64 2.29 2.56 2.64 2.73 ...
151564 O9.5IV 0.38 0.58 1.55 2.29 2.74 3.76 : 4.95 ...
151804 O8Ifp 0.37 ...... 2.92 3.24 ......
152217 B0III 0.43 0.49 1.16 2.07 2.33 2.49 2.42 ... 226 A. A.
Table5
continued
E k k k k k k k
V R I J H K L M
HD Sp/L B
152218 O9.5IV 0.44 0.68 1.61 2.41 2.75 2.93 2.98 ...
152234 B0.5Ia 0.29 ...... 4.07 4.34 ......
152235 B1Iae 0.69 ...... 2.59 2.96 3.16 3.35 ...
152236 B1Iape 0.68 ...... 2.53 2.91 3.24 3.51 ...
152245 B0III 0.35 0.43 1.11 1.86 2.31 2.43 2.14 ...
152246 O9III 0.43 0.58 1.65 2.16 2.60 2.65 2.93 ...
152247 O9.5II 0.42 0.67 1.50 2.36 2.86 2.83 3.17 ...
152386 O6I 0.83 0.65 1.40 2.27 2.89 2.84 3.40 ...
152405 O9.5I 0.38 0.63 1.55 2.37 2.66 2.63 3.13 ...
152408 O8Ib 0.45 ...... 3.29 3.60 ......
152424 O9Ia 0.65 ...... 2.78 2.98 ......
152478 B3Vnep 0.16 ...... 3.44 4.13 5.38 7.56 ...
152560 B0.5IV 0.37 0.62 1.51 2.08 2.57 2.49 ......
152667 B0.5Iae 0.46 ...... 2.41 2.91 3.09 3.33 3.33
152723 O7 0.39 ...... 3.54 3.87 3.77 ......
153261 B2IVne 0.18 ...... 1.89 2.61 4.00 6.89 8.83
153426 O9II 0.41 0.63 1.41 2.20 2.51 2.37 2.61 ...
153919 O6.5Iae 0.59 ...... 2.42 2.73 3.02 3.44 3.59
154043 B1I 0.81 ...... 2.47 2.80 3.02 3.16 ...
154090 B1Iae 0.45 0.80 1.51 2.44 2.78 3.00 3.00 ...
154368 O9Ia 0.65 ...... 2.69 3.32 3.54 3.29 ...
154445 B1V 0.39 0.95 1.69 ......
155806 O8Ve 0.275 1.58 3.00 4.33 5.05 5.89 7.56 8.65
155851 B0Ve 0.39 ...... 4.13 4.92 ......
155889 O9IV 0.27 0.63 1.67 2.11 2.78 2.85 3.00 ...
156201 B0.5Ia 0.85 ...... 2.44 2.82 3.00 3.13 ...
156738 O7 1.17 ...... 2.45 2.72 2.91 3.03 ...
157038 B4Ia 0.72 ...... 2.88 3.31 3.57 3.79 ...
157246 B1Ib 0.06 ...... 2.83 3.17 3.33 : 2.50 ...
157857 O7f 0.47 ...... 2.38 2.64 2.87 3.30 ...
158186 O9.5V 0.30 0.57 1.60 2.13 2.47 2.53 2.63 ...
158864 B0Ve 0.26 1.04 2.42 3.27 4.38 5.54 7.54 ...
159090 O9.5II 0.40 0.58 1.33 2.23 2.58 2.60 2.80 ...
159176 O7V 0.33 0.79 1.79 2.76 3.06 3.18 3.45 2.27
159864 B0.5II 0.44 ...... 2.07 2.39 2.48 2.55 ...
161056 B1.5V 0.60 0.78 1.57 2.12 2.45 2.67 2.73 ...
161061 B2III 0.96 ...... 2.13 2.42 2.66 2.73 ...
161653 B0.5Ib 0.20 0.60 1.55 2.55 : 1.80 2.60 2.55 ...
161961 B0.5III 0.45 ...... 2.04 2.29 2.51 2.60 ...
162978 O8II 0.34 0.68 1.47 2.03 2.38 2.56 2.71 2.88
163522 B1Ia 0.19 0.63 1.63 2.11 2.58 2.84 3.26 ...
163758 O6.5Ia 0.35 0.60 1.40 1.91 2.34 2.57 3.09 ...
163800 O7I 0.59 0.63 1.39 2.20 2.42 2.61 2.73 ...
163892 O9V 0.39 0.67 1.67 2.38 2.77 2.90 3.08 ...
164284 B2Vne 0.18 ...... 3.83 4.67 6.83 9.28 ...
164353 B5Ib 0.10 1.00 1.60 ...... 3.90 3.10 : 5.00 Vol. 43 227
Table5
continued
E k k k k k k k
V R I J H K L M
HD Sp/L B
164402 B0Ib 0.20 0.95 1.95 3.10 3.35 3.65 3.70 ...
164492 O7.5III 0.28 ...... 2.61 : 4.86 : 11.64 ...
164536 B3 0.15 ...... 2.80 3.27 ......
164794 O4V 0.30 : 1.33 : 2.33 2.87 3.27 3.40 3.43 3.33
164816 B0V 0.26 0.62 1.62 2.15 2.65 2.38 2.73 ...
164865 B9Iab 0.85 ...... 2.73 3.25 3.55 3.99 ...
164906 B0ne :0.47 ...... 2.74 3.49 4.17 4.94 ...
165016 B0III 0.19 0.32 1.53 1.84 2.26 2.84 2.79 ...
165024 B2Ib 0.10 ...... 2.40 2.20 2.20 : 1.70 ...
165052 O7n 0.37 ...... 3.11 ......
165319 B0Ia 0.81 ...... 2.35 : 1.73 2.83 2.95 3.44
165516B0.5Ib 0.32 ...... 2.94 3.38 : 4.72
165921 O7.5V 0.405 ...... : 1.04 3.28 : 4.69
166033B5 0.35 ...... : 4.51 3.54 ...
166197 B1V 0.09 ...... 2.89 3.22 3.56 3.33 ...
166546 O9III 0.31 0.68 1.35 2.06 2.26 2.58 2.42 ...
166628 B3Ia 0.72 ...... 2.35 2.74 2.93 2.99 ...
166734 O8e 1.375 0.90 1.72 2.26 ... 2.75 2.88 3.11
167128 B3IIIep 0.11 0.91 1.55 1.73 2.55 3.00 4.27 : 5.36
167451 B0.5Ib 0.99 ...... 2.17 2.55 2.74 2.91 ...
167838 B5Ia 0.56 ...... 2.39 2.73 2.96 3.11 2.86
167971 O8I 1.06 0.60 1.30 2.41 2.78 2.89 3.08 ...
168075 O8 0.725 ...... 2.52 2.83 3.03 ......
168137 O8v 0.675 ...... 2.07 2.56 2.83 ......
168476 B5p 0.14 ...... 2.43 2.64 3.36 ......
168571 B4II 0.64 ...... 2.41 2.84 3.13 3.08 ...
168625 B8Ia 1.49 ...... 2.29 2.66 2.91 3.12 3.68
168797 B3Vne 0.14 ...... 1.57 : 0.64 2.43 : 4.71 ...
169034 B5Ia 1.33 ...... 2.43 2.83 3.08 3.26 ...
169454 B1Iae 1.13 ...... 2.35 2.73 2.96 3.12 3.43
169582 O5I 0.87 0.60 1.33 2.25 2.71 2.95 2.85 ...
169754 B0.5I 1.26 ...... 2.08 2.42 2.61 2.78 2.92
170235 B2IVpe 0.28 ...... 2.57 2.75 3.46 : 8.25
170740 B2V 0.45 ...... 2.18 2.29 2.51 2.64 ...
170938 B1Ia 0.98 ...... 2.62 3.01 3.22 3.42 ...
171012 B0.5Iae 0.66 ...... 2.38 2.71 2.94 3.18 ...
171589 O7.5V 0.61 0.66 1.46 2.23 2.49 2.67 2.39 ...
172252 B0Ve 0.91 ...... 2.27 2.59 3.00 3.45 ...
172275 O6 1.09 0.59 1.29 2.02 2.30 2.48 2.66 ...
172488 B0.5V 0.78 ...... 2.13 2.38 2.60 2.60 ...
172694 B1Ve 0.43 ...... 3.60 4.51 5.33 ...
173438 B0.5Ia 1.00 ...... 2.02 2.42 2.48 ......
174638 B7Ve 0.13 1.38 2.46 3.77 4.77 5.69 8.08 9.92
175754 O8III 0.20 0.75 1.75 2.20 2.50 2.80 3.20 ...
175876 O6.5III 0.20 0.70 1.55 2.00 2.15 2.30 2.70 ...
176270 B8VIV 0.08 ...... 5.00 4.50 5.75 ...... 228 A. A.
Table5
continued
E k k k k k k k
V R I J H K L M
HD Sp/L B
177291 B8e :0.52 ...... 4.44 4.85 5.25 ...
178175 B2Ve 0.10 0.70 1.90 7.10 7.80 9.70 12.1 ...
179406 B3V 0.32 ...... 2.09 2.28 2.50 2.63 ...
183143 B7Iae 1.28 : 2.43 1.64 2.34 ... 2.72 2.91 3.02
183362 B3Vne 0.04 ...... 7.75 8.75 17.00 19.3 ...
184915 B0.5III 0.22 0.73 1.23 1.86 2.23 2.64 3.05 3.09
184943 B8Iae 0.75 0.85 1.61 2.21 2.55 2.68 2.89 3.36
185268A B5V :0.06 ...... 1.00 1.00 4.00 ...
185859 B0.5Iae 0.59 ...... 2.41 2.56 2.80
186745/ B8Iae 0.96 ...... 2.59 2.71 2.88
186841 B1Ia 0.97 0.85 1.53 ...... 2.12 2.28 ...
186842 B8 0.44 ...... 2.27 2.66 3.07 3.05 ...
186882 B9.5IV 0.04 0.00 0.75 4.00 3.50 3.00 3.50 2.75
187811 B2.5Ve 0.055 ...... 2.91 2.73 5.45 11.1 ...
188001 O8f 0.295 ...... 3.36 3.36 ...
190066 B1Iab 0.37 0.51 1.16 1.92 2.30 2.27 2.57 ...
190429A O5ef 0.46 ...... 2.65 2.80 2.87 ...
190603 B1.5Iae 0.71 0.80 1.56 2.18 2.73 2.82 2.82 3.18
190944 B1.5Ve 0.45 ...... 3.44 3.58 3.91 5.51 ...
191610 B2.5Vne 0.065 ...... 4.00 5.08 8.46 15.2 ...
191639 B1V 0.08 ...... 2.13 1.88 2.63 3.13 ...
192422 B0.5Ib,II 0.70 ...... 2.67 2.88 3.27
192964 B2.5Iae 0.40 0.85 1.70 2.50 2.78 3.08 3.25 ...
193237 B2pe 0.63 1.00 1.71 2.40 2.89 3.27 3.94 : 4.81
193322 O9V 0.38 0.79 1.56 ......
193443 O9III 0.65 0.77 1.37 ......
193514 O7e 0.74 ...... 2.77 2.69 ...
194279B1.5Ia 1.10 ...... 2.97 3.21 3.34
194839 B0.5Iae 1.19 ...... : 1.96 3.00 3.03
195407 B0IVe 0.59 ...... 3.44 4.05 4.93 ...
198478 B3Iae 0.53 0.83 1.58 ...... 2.66 2.64 2.79
198931 B1Ve 0.83 ...... 2.95 3.41 3.71 ...
199216B1II 0.67 ...... 2.39 2.45 2.55
199356 B2IVe 0.36 ...... 4.06 4.97 ......
199478 B8Ia 0.50 0.88 1.72 ...... 2.72 2.96 3.08
199579 O6Ve 0.35 ...... 2.77 2.83 ...
200120 B1Ve 0.18 ...... 0.39 0.94 2.22 ......
200775 B2Ve 0.58 ...... 4.24 5.84 7.90 ...
200857B3III 0.72 ...... 5.97 6.21 6.14
202850 B9Iab 0.13 0.77 2.08 2.08 3.23 3.62 2.85 ...
202904 B2Ve 0.10 1.60 2.70 5.10 6.50 8.80 12.0 ...
203467 B3IVe 0.14 ...... 3.00 3.64 5.43 8.29 ...
203532 B3IV 0.31 ...... 2.10 2.26 2.61 2.74 ...
203938B0.5IV 0.70 ...... 2.77 2.91 3.06
204827 B0V 1.08 0.77 1.44 ...... 2.51 2.63 2.44
206165 B2Ib 0.46 0.80 1.41 1.83 ... 2.20 2.37 ... Vol. 43 229
Table5
concluded
E k k k k k k k
V R I J H K L M
HD Sp/L B
206183 B0V 0.40 ...... 2.00 2.48 ......
206773 B0Ve 0.49 ...... 3.53 4.47 ......
207198 O9IIe 0.58 0.71 1.31 1.93 ... 2.28 ......
208501 B8Ib 0.77 0.83 1.65 ...... 2.51 2.79 2.91
208682 B2.5Ve 0.135 ...... 2.30 2.15 5.04 10.5 ...
209008 B3III :0.12 ...... : 0.50 : 0.75 : 0.92 : 0.58 ...
209975 O9Ib 0.35 0.80 1.40 1.91 ... 2.54 ......
210839 O6If 0.57 0.74 1.39 2.09 2.26 2.44 2.70 2.65
212044 B1Ve 0.27 ...... 3.33 4.33 ......
212076 B2IVVe 0.08 0.63 1.00 ......
212571 B1Ve 0.20 2.50 2.55 4.55 5.50 7.25 9.65 11.8
212593 B9Iab 0.10 0.70 2.00 2.50 3.30 3.60 3.40 3.70
214680 O9V 0.08 0.75 1.25 : 1.00 : 4.00 : 1.50 2.50 ...
216411 B1Iae 0.79 ...... 2.91 3.09 3.37
216898 O8.5V 0.815 ...... 2.44 2.63 ...
217050 B4IIIpe 0.07 ...... 8.29 11.0 17.0 24.71
217101 B2IVV 0.06 ...... 1.83 1.50 1.67 2.17 ...
217543 B3Vpe 0.07 ...... 1.71 1.57 ......
218342B0IV 0.68 ...... 2.53 2.72 ...
218537 B3V 0.16 ...... 2.44 ... 3.38 ......
219287 B0Iae 1.24 ...... 2.84 2.92 ...
224151B0.5IIv 0.41 ...... 2.66 2.86 3.10
225094 B3Iae 0.46 0.80 1.50 ...... 2.67 2.93 2.57
225095 B1Ve 0.21 ...... 3.43 3.90 ......
225146B0Ib 0.59 ...... 2.63 2.61 ...
225160 O8e 0.555 ...... 3.06 3.55 ...
225985 B1Ve 0.33 ...... 3.45 4.36 ......
226868 B0Ib 1.06 ...... 2.44 2.69 2.84 3.06 3.41
227460 B0.5V 0.40 ...... 3.25 ......
228712B0.5Ia 1.33 ...... 2.93 3.10 3.09
229033 B0II III 0.95 ...... 2.61 2.58 ...
229059 B1.5Iap 1.70 ...... 2.61 2.78 2.88
236689 B1.5Ve 0.50 ...... 2.12 2.24 2.76 ......
249845 B2V 0.29 ...... 2.10 2.34 ......
250028 B2Ve 0.44 ...... 3.00 3.98 ......
254577 B0.5II III 1.04 ...... 2.79 3.01 ...
259431 B6e :0.42 ...... 3.69 5.45 8.05 11.3 13.5
259597 B0.5Ve 0.37 ...... 3.51 3.74 ......
269006 B2.5Iap 0.15 3.60 4.60 11.07 11.7 13.1 ......
290813 B8 0.62 ...... 2.37 2.76 3.02 3.29 ...
306097 O9III 0.92 ...... 2.20 2.49 2.64 2.80 ...
394926 B9II III :0.22 ...... : 1.00 ......
404220 O7e 1.99 ...... 2.78 2.97 3.04
404227 O6 1.60 ...... 2.53 2.71 2.86 2.94
414064 B3 0.47 ...... 3.30 3.51 ......
602522 O6.5III 0.71 ...... 2.90 3.17 3.04 : 6.51 230 A. A.
Every color excess ratio suffers the error following the incorrectness of the
measured UV ¯ux as well as the photometric inaccuracies:
i
2 h 2
k E
1 V
2 2 2 2 B
= + + + ( )
0 7
k m V
m
E E
B V B V
z z
2 2 1 2
where:
m ± root-mean-square deviation of the observations at wavelength
Ê
V ± root-mean-square deviation of the observations at wavelength 5550 A,
0 ± "arti®cial" standard error from PKW,
m
E ± color excess error
B V
0
V
( )
For m and a value 0.01 was adopted, does not exceed 0.02 in
m( )
R,I,J passband, 0.03 in H,K,L passband and 0.05 in M passband (Wegner ± in
k ( ) =
(B V ) preparation), E does not exceed 0.03 and 1.
Note a good agreement between this result and that of Harris (1973), who
= deduced R 3 15 0 20 by the cluster method.
There is no clear evidence for regional variation of R with galactic longitude.
R = E (K V )
Smyth and Nandy (1978) deduced K 3 12 0 05 from the vs.
(B V ) l =
E diagram for 40 stars in the galactic anticentre region ( 160 235 ).
R =
However, Whittet and van Breda (1980) reported the value K 3 05 0 05 in
(K V ) E (B V )
this direction (this value is calculated from E vs. diagram)
R = R = olar
and the value 3 08 calculated from polarization measurements ( p
5 6 max ± Whittet and van Breda 1978). In longitude interval 200 30
R =
Whitted and van Breda (1978 and 1980) reported the values K 3 12 0 05
R = R =
K olar
and p 3 15. In longitude interval 10 215 these authors reported
R = olar
2 96 0 05 and p 2 96 respectively (Sneden et al. 1978 deduced from 98
E (K V ) E (B V ) R =
northen Milky Way stars and vs. diagram K 3 01
0 05).
Our results in these longitude intervals are in direction of:
=
l 160 235 3 18 0 12
=
l 200 30 3 00 0 11
=
l 10 215 3 04 0 11
(K V ) E (B V ) Figs. 7±8 show the plots of E vs. for the stars in the Orion and Sco-Oph dark cloud regions. In both cases the best straight lines lead to the R
value substantially greater than the normal value:
R =
K 3 21 0 12 (Orion)
R =
K 3 30 0 12 (Sco-Oph)
These values disagree with the results obtained by Whittet and van Breda
Vol. 43 231
(K V ) E (B V )
Fig. 7. Plot of E against for stars in Orion dark cloud region.
(K V ) E (B V ) Fig. 8. Plot of E against for stars in Sco-Oph dark cloud region.
(1978), namely:
R =
K 4 0 0 5 (Orion)
R =
K 3 9 0 1 (Sco-Oph)
( V ) E (B V ) Fig. 9 shows the relation between E vs. inverse wave- length. The size of points represents the mean standard deviation in IR passband.
4
The analytical curve ®tted to the observed "mean galactic" extinction law ( ) is
= R = also presented. The obtained result for 1 0 gives 3 10 0 05. The whole extinction curve, which really represents the true "mean galactic curve" in near infrared ranges (in other words: the long distance average), is listed in Table 6. 232 A. A.
Fig. 9. The mean galactic extinction curve derived from photometric measurements (near IR region).
Table6
An average interstellar extinction curve
E ( V )
1 1
[ m ]
E (B V ) 2.91 1.74 0.01 2.27 1.00 0.00 1.82 0.00 0.00
1.43 0.725 0.012
1.14 1.527 0.020
0.80 2.327 0.029
0.61 2.683 0.024
0.45 2.826 0.022
0.29 3.010 0.027
0.20 3.100 0.047
3. Discussion
The results reported in this paper con®rm the existence of a great variety of extinction curves in our Galaxy. One can thus argue that the dark interstellar clouds are populated with solid particles differing in their chemical compositions, sizes, shapes etc. Extinction towards distant objects is almost certainly dominated by the "diffuse cloud component". Nearby stars allow us to derive extinction law in remnants of the parent clouds of the neighboring star clusters or associations.
Acknowledgements. I would like to express my deep gratitude to all Col- leagues who contributed to this paper with valuable discussion or comments. My Vol. 43 233 special thanks are due to Prof. W. Iwanowska, Prof. J.Kreøowski and Mr. J. Papaj for critical reading of the manuscript.
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