Oke (1990) Spectrophotometric Standards

Oke (AJ, 99, 1621, 1990) has provided absolute spectral energydistributions covering the wavelength range 3200 to 9200A in AB magnitudes for 25 stars. The measurements were made with the Double Beam Spectrogrpph of the Hale 5m telescope. The reduced magnitudes are tabulated at 1A intervals from3300 to 4700A and at 2A intervals from 4700 to 9200A. Comparisonof the fluxes with those determined elsewhere showed that Oke'sabsolute magnitudes are systematically brighter by 0.04 mag. Themagnitudes and fluxes plotted have been corrected for this effect.Colina & Bohlin (AJ, 1931, 1994) tabulate the differencesbetween the original Oke fluxes, in terms of synthesized B and Vmagnitudes, and Landolt photometry for each star individually.The AB magnitudes were converted to flux (ergs/cm/cm/s/A) usingthe formula
ABMAG = -2.5 alog10(Fnu) - 48.59
(Hamuy et al., PASP, 104, 533, 1992), where Fnu is in ergs/cm/cm/s/Hz.

 

 No.   Name         alpha (2000) delta     Sp.     V     AB
Type (5460A)
---------------------------------------------------------------
1 G158-100 00 33 54.3 -12 07 57 sdG 14.89 14.82
2 HZ 4 03 55 21.7 +09 47 19 DA4 14.52 14.47
3 G191B2B 05 05 30.6 +52 49 54 DAO 11.78 11.72
4 G193-74 07 53 27.4 +52 29 36 DC 15.70 15.58
5 BD+75d325 08 10 49.3 +74 57 57 O5p 9.54 9.52
6 Feige 34 10 39 36.7 +43 06 10 DO 11.18 11.13
7 HD 93521 10 48 23.5 +37 34 13 09Vp 7.04 6.96
8 HZ 21 12 13 56.4 +32 56 31 DO2 14.68 14 67
9 Feige 66 12 37 23.6 +25 04 00 sdO 10.50 10.43
10 Feige 67 12 41 51.8 +17 31 20 sdO 11.81 11.78
11 G60-54 13 00 09.5 +03 28 56 DC 15.81 15.73
12 HZ 44 13 23 35.4 +36 08 00 sdO 11.66 11.65
13 GRW+70d5824 13 38 51.8 +70 17 08 DA3 12.77 12.72
14 BD+33d2642 15 51 59.9 +32 56 55 B2IV 10.81 10.74
15 G138-31 16 27 53.6 +09 12 24 DA7 16.14 16.07
16 G24-9 20 13 56.0 +06 42 55 DC 15.72 15.77
17 BD+28D4211 21 51 11.1 +28 51 52 Op 10.51 10.47
18 B0+25d4655 21 59 39.3 +26 25 42 9.76 9.65
19 LTT 9491 23 19 35.0 -17 05 30 DC 14.04 14.06
20 Feige 110 23 19 58.4 -05 09 56 DOp 11.82 11.81
21 GD 248 23 26 06.7 +16 00 21 DC 15.09 15.08
22 GD 50 03 48 50.1 -00 58 30 DA2 14.06 14.06
23 SA95-42 03 53 43.7 -00 04 33 15.61 15.60
24 GD 108 10 00 47.3 -07 33 31 sdB? 13.56 13.57
25 NGC 7293 22 29 38.5 -20 50 13 13.51 13.48

Note: The ABMAG listed for HZ 4 in Table 1 of Oke (1990) is in error.The value should be 14.47.