P. Massey led a group at KPNO to obtain observations of 25 stars with nearly featureless spectra to be used as standards at various spectroscopic resolutions. These results were published in two papers: (1) Massey et al. (1988) and (2) Massey and Gronwall (1990). The former paper covers wavelengths from 3200Å to 8100Å and the latter paper extends the wavelength coverage to 10200Å for 11 of the standard stars in the former paper. Both papers present the AB magnitudes of the standards at 50Å intervals. The AB magnitudes are converted to flux using the formula:
AB Mag = -2.5 Log(F) - 48.59 where F is in units of erg cm-2 s-1 Hz-1 using the flux calibration of Vega by Hayes and Latham (1975).
Massey Spectrophotometric Standards1 | |||||||
Star | RA2 (J2000) |
DEC2 (J2000) |
Type | V3 | B-V3 | m5556 | Plots4 |
PG 0205+134 | 02:08:03.5 | +13:36:31 | sdOB | (14.73) | (-0.05) | 14.87 | DSS Blue/DSS Red/Spectrum |
PG 0216+032 | 02:19:19.0 | +03:26:54 | sdOC | (14.56) | (-0.25) | 14.79 | DSS Blue/DSS Red/Spectrum |
PG 0310+149 | 03:13:37.0 | +15:06:24 | sdO | (15.50) | (-0.07) | 15.63 | DSS Blue/DSS Red/Spectrum |
HZ 14 | 04:41:01.5 | +10:59:41 | dA | ... | ... | 14.01 | DSS Blue/DSS Red/Spectrum |
G 191B2B | 05:05:30.6 | +52:49:56 | dAwk | 11.80 | -0.32 | 11.85 | DSS Blue/DSS Red/Spectrum |
Hiltner 600 | 06:45:13.4 | +02:08:14 | B1V | 10.45 | +0.18 | 10.42 | DSS Blue/DSS Red/Spectrum |
PG 0823+546 | 08:26:50.4 | +54:28:06 | sdOC | ... | ... | 14.36 | DSS Blue/DSS Red/Spectrum |
PG 0846+249 | 08:49:04.7 | +24:45:16 | DA1 | ... | ... | 16.94 | DSS Blue/DSS Red/Spectrum |
PG 0934+554 | 09:38:19.9 | +55:05:43 | sdO | 12.16 | -0.26 | ... | DSS Blue/DSS Red/Spectrum |
PG 0939+262 | 09:42:51.2 | +26:00:58 | DA1 | (14.66) | (-0.28) | 14.89 | DSS Blue/DSS Red/Spectrum |
Feige 34 | 10:39:36.9 | +43:06:11 | sdO | 11.23 | -0.30 | 11.25 | DSS Blue/DSS Red/Spectrum |
PG 1121+145 | 11:24:15.9 | +14:13:49 | DA1 | 16.63 | -0.22 | 16.97 | DSS Blue/DSS Red/Spectrum |
GD 140 | 11:37:05.3 | +29:47:51 | DA2 | 12.50 | -0.06 | 12.50 | DSS Blue/DSS Red/Spectrum |
EG 81 | 11:37:26.8 | +14:10:21 | sdO | 13.21 | -0.26 | 13.30 | DSS Blue/DSS Red/Spectrum |
Feige 66 | 12:37:23.5 | +25:04:01 | sdO | ... | ... | 10.54 | DSS Blue/DSS Red/Spectrum |
Feige 67 | 12:41:48.9 | +17:30:58 | sdO | 11.82 | -0.32 | 11.89 | DSS Blue/DSS Red/Spectrum |
HZ 44 | 13:23:35.5 | +36:08:01 | sdO | 11.68 | -0.29 | 11.74 | DSS Blue/DSS Red/Spectrum |
PG 1545+035 | 15:48:24.3 | +03:22:54 | sdOB | ... | ... | 14.34 | DSS Blue/DSS Red/Spectrum |
PG 1708+602 | 17:09:15.9 | +60:10:11 | sdOC | (13.70) | (-0.25) | 13.92 | DSS Blue/DSS Red/Spectrum |
HD 192281 | 20:12:33.2 | +40:16:06 | O5f | 7.55 | +0.38 | 7.44 | DSS Blue/DSS Red/Spectrum |
Cyg OB2 No.9 | 20:33:10.8 | +41:15:08 | O5If | 10.80 | 1.93 | 10.70 | DSS Blue/DSS Red/Spectrum |
Wolf 1346 | 20:34:22.3 | +25:03:53 | DA | 11.54 | -0.07 | 11.59 | DSS Blue/DSS Red/Spectrum |
BD +28 4211 | 21:51:11.2 | +28:51:53 | sdOp | 10.53 | -0.34 | 10.56 | DSS Blue/DSS Red/Spectrum |
HD 217086 | 22:56:47.2 | +62:43:38 | O5 | 7.65 | +0.63 | 7.49 | DSS Blue/DSS Red/Spectrum |
Feige 110 | 23:19:58.4 | -05:09:56 | sdO | 11.50 | -0.32 | 11.88 | DSS Blue/DSS Red/Spectrum |
1 The information is this table is adaped from Table 1 of Massey et al. (1988).
2 The J2000 coordinates of the standards were measured from the Digital Sky Survey images of the stars.
3 Values in parenthesis are the v and g - v indices of Green, Schmidt, and Liebert (1986), which roughly correspond to V and B - V.
4The finding charts were made using Digital Sky Survey data. The "blue" finding charts were made using the POSS-II J survey data obtained with the IIIaJ emulsion and a GG395 filter. The "red" finding charts were made using the POSS-II F survey data obtained with the IIIaF emulsion and an RG610 filter. The exceptions to this are the finding charts for Feige 110, which were made using the SERC-EJ and SERC-ER survey data respectively. The spectral plots were made using the ASCII text files from the IRAF NOAO 1-D Standards library "spec50cal".