Our preferred list of standards, obtained with modern linear detectors at good resolution, are listed below. Finder charts for these standards are available from ESO or from APO . The standard star names link to IRAF compatible calibration files prepared by Greg Aldering. Our primary standards are those of Bohlin et al.; Our preferred smooth-spectrum star is EG131, but it is visible only part of the year. The next largest set of standards are those from Hamuy. Note that Oke standards don't have complete wavelength coverage, but when combined with the other standards, we can calibrate them ourselves as long as several better standards are observed on the same night. Stars with declination below -40 degrees or secondary standards fainter than 13th magnitude are not considered. Bright stars may require that the telescope be defocused. Old spectrophotometric standards, having only very low resolution calibration, are still commonly listed at many observatories but should be avoided.
High-Quality Spectrophotometric Standards
Name RA (J2000) Dec V Mag Type Spec Chart Notes
HR9087 00 01 49.42 -03 01 39.0 5.12 B7III H* Hayes 1970 dozen
LTT377 00 41 46.82 -33 39 08.2 11.23 F H ?
LTT1020 01 54 49.68 -27 28 29.7 11.52 G H
HR718 02 28 09.54 +08 27 36.2 4.28 B9III HS* Hayes 1970 dozen
LTT1788 03 48 22.17 -39 08 33.6 13.16 F H
HR1544 04 50 36.69 +08 54 00.7 4.36 A1V H -
G191B2B 05 05 30.62 +52 49 54.0 11.78 DA1 BOMS B
GD71 05 52 27.51 +15 53 16.6 13.03 DA1 B B
LTT2415 05 56 24.30 -27 51 28.8 12.21 sdG H
Hiltner600 06 45 13.33 +02 08 14.1 10.44 B1V HM M
BD+75325 08 10 49.31 +74 57 57.5 9.54 O5p BO T
HR3454 08 43 13.46 +03 23 55.1 4.30 B3V H* Hayes 1970 dozen
AGK+81266 09 21 19.06 +81 43 28.6 11.92 sdO BO -
LTT3864 10 32 13.90 -35 37 42.4 12.17 F H
Feige34 10 39 36.71 +43 06 10.1 11.18 DO BOMS T
HD93521 10 48 23.51 +37 34 12.8 7.04 O9Vp BOS T
HR4468 11 36 40.91 -09 48 08.2 4.70 B9.5V HS* Hayes 1970 dozen
Feige56 12 06 42.23 +11 40 12.6 11.06 B5p H
HZ21 12 13 56.42 +32 56 30.8 14.68 DO2 BOS T
Feige66 12 37 23.55 +25 04 00.3 10.50 sdO OMS T
Feige67 12 41 51.83 +17 31 20.5 11.81 sdO OMS T
GD153 12 57 02.37 +22 01 56.0 13.35 DA1 B B
HR4963 13 09 56.96 -05 32 20.5 4.38 A1IV H* Hayes 1970 dozen
HZ43 13 16 21.99 +29 05 57.0 12.91 DA1 B B
HZ44 13 23 35.37 +36 08 00.0 11.66 sdO BOMS T
CD-32d9927 14 11 46.37 -33 03 14.3 10.42 A0 H
HR5501 14 45 30.25 +00 43 02.7 5.68 B9.5V H -
P041C 14 51 58.19 +71 43 17.3 12.00 GV B solar analog
LTT6248 15 39 00.02 -28 35 33.1 11.80 A H
BD+332642 15 51 59.86 +32 56 54.8 10.81 B2IV OS T
P177D 15 59 13.59 +47 36 41.8 13.47 GV B solar analog
EG131 19 20 35.00 -07 40 00.1 12.3 DA b smooth spectrum variable star 2
HR7596 19 54 44.80 +00 16 24.6 5.62 A0III H* Hayes 1970 dozen
HR7950 20 47 40.55 -09 29 44.7 3.78 A1V H* Hayes 1970 dozen
BD+284211 21 51 11.07 +28 51 51.8 10.51 Op BOMS T 1
BD+254655 21 59 42.02 +26 25 58.1 9.76 O O T
BD+174708 22 11 31.37 +18 05 34.2 9.91 sdF8 - SDSS primary calibrator
NGC7293 22 29 38.46 -20 50 13.3 13.51 V.Hot O T
HR8634 22 41 27.64 +10 49 53.2 3.40 B8V H -
LTT9239 22 52 40.88 -20 35 26.3 12.07 F H
LTT9491 23 19 34.98 -17 05 29.8 14.11 DC HO T
Feige110 23 19 58.39 -05 09 55.8 11.82 DOp BHOMS T
Codes for References:
B: Bohlin, Colina, & Finley (1995), AJ, 110, 1316. (These extend from UV to NIR)
Bohlin, Dickinson, & Calzetti (2001), AJ, 122, 2118. (STIS optical added)
H: Hamuy, Walker, Suntzeff, Gigoux, Heathcote, & Phillips (1992), PASP, 104, 533
& Hamuy, Suntzeff, Heathcote, Walker, Gigoux, & Phillips (1994), PASP, 106, 566
These extend from 3300A to 10200A. Aldering has performed atmospheric absorption
correction for these.
H*: Indicates Hamuy et al standards with absolute flux calibration in
Hayes (1970), Ap. J. 159, 165.
M: Massey & Gronwall (1990), ApJ, 358, 344. These extend to 10200A.
O: Oke (1990), AJ, 99, 1621. These extend from 3200A to 9200A
S: Stone (1996), ApJS, 107, 423. These extend from 4040A to 8800A.
T: Turnshek, Bohlin, Williamson, Lupie, Koornneef, & Morgan (1990), AJ, 99, 1243
b: Bessell (1999), PASP, 111, 1426.
Hayes 1970 dozen refers to the 12 stars compared to an absolute lamp calibration
in Hayes 1970, ApJ, 159, 165
Notes:
1: Red companion 2.8" away at PA = 340. About 5 mag dimmer in V.
2: This star is a near-perfect blackbody, having only a few weak lines in blue
Removed due to broad lines: GRW+705824 13 38 51.77 +70 17 08.5 12.77 DA3 BO T EG274 16 23 33.75 -39 13 47.5 11.03 DA H LTT7987 20 10 57.38 -30 13 01.2 12.23 DA H LTT3218 08 41 34.10 -32 57 00.1 11.86 DA H