Flux Standards

  • It is recommended that you observe a flux standard at least once per run, so that the shapes of each order may be mapped.  The telescope operators have catalogs containing these standards.   We recommend that you take one of the "Standards recommended by the HIRES webpage".
  • A list of references to standard stars of various sorts can be found at the SOFA (Standard Objects for Astronomy) website.
  • Finding charts for flux standards may be found here.  
  • HST standard flux files:  TAR  Directory

Standards recommended by HIRES web page

Name
RA(2000) Dec(2000) V
Type     Finding Chart       Spectrum*
G191B2B
05 05 30.6 +52 49 54 11.8
DAO        GIF  FITS              JPG
Feige 34
10 39 36.7 
+43 06 10 11.2
DO           GIF  FITS              JPG
Feige 67 12 41 51.8 +17 31 20 11.8
sdO          GIF  FITS              JPG
BD+28 4211 21 51 11.1 +28 51 52 10.5
Op            GIF  FITS              JPG
Feige 110 23 19 58.4 -05 09 56 11.8
DOp
    GIF  FITS               JPG

Standard Stars to be avoided, due to strong absorption: Feige 66, HZ44, Grw+705824, BD+33 2642

* From Massey et al (1988)


CTIO Echelle Flux Standards

These have calibrations at 16A intervals. Data from Hamuy 1992,1994 PASP 104, 533

Secondary Standard Stars

HR Star RA (2000) DEC MK Type (U-B) (B-V) V (V-R) (V-I)

9087 29 Psc 00 01 49.3 -03 01 39 B7 III-IV -0.501 -0.136 5.120 -0.052 -0.122
718 xi^2 Cet 02 28 09.5 08 27 36 B9 III -0.107 -0.056 4.279 -0.023 -0.063
1544 pi^2 Ori 04 50 36.7 08 54 01 A1 V --- 0.01 4.355 0.014 0.039
3454 eta Hya 08 43 13.4 03 23 55 B3 V -0.743 -0.200 4.295 -0.083 -0.200
4468 theta Crt 11 36 40.8 -09 48 08 B9.5 V -0.18 -0.07 4.700 -0.023 -0.063
4963 theta Vir 13 09 56.9 -05 32 20 A1 IV -0.01 -0.00 4.375 0.003 0.010
5501 108 Vir 14 45 30.1 00 43 02 B9.5 V -0.080 -0.023 5.681 0.004 -0.026
7596 58 Aq1 19 54 44.7 00 16 25 A0 III -0.01 0.10 5.62 --- ---
7950 epsilon Aqr 20 47 40.5 -09 29 45 A1 V 0.029 -0.001 3.778 -0.005 -0.010
8634 zeta Peg 22 41 27.6 10 49 53 B8 V -0.24 -0.09 3.40 -0.037 -0.079


List of spectrophotometric standards from Jeremy Walsh.

  The HST spectrophotometric standards cover the approximate wavelength range  800 to 12,000 Angstrom.
The following table gives summary details for the standard stars. It was assembled from SIMBAD (in July 2002) and consequently the data are somewhat heterogenous. Similar data are available in Table 1 of Turnshek et al. (1990). The Turnshek et al. and SIMBAD V
magnitudes usually agree to within a few tenths of a magnitude, but there are some significant differences in the spectral types. Turnshek et al.
give the following position for BPM 16274: 0 50 03.18, -52 08 17.4, which may be preferable to the unusually imprecise SIMBAD position. An asterisk
(`*') in the final column of the table indicates that the star is also included in the companion set of Oke spectrophotometric standards.

Star R.A. Dec. V Sp. Oke
Name (2000) (2000) Type
AG+81 266 09 21 19.1801 +81 43 27.642 12.10 B2
Alpha Lyr 18 36 56.3364 +38 47 01.291 0.03 A0V
BD+28 4211 21 51 11.0222 +28 51 50.364 10.54 Op *
BD+33 2642 15 51 59.8855 +32 56 54.324 10.81 B2IVp *
BD+75 325 08 10 49.4903 +74 57 57.929 9.50 O5pvar *
BPM 16274 00 50.1 -52 09 14.16 DA...
Eta UMA 13 47 32.4377 +49 18 47.754 1.852 B3V
Feige 110 23 19 58.3977 -05 09 56.207 11.4 DA: *
Feige 34 10 39 36.7400 +43 06 09.252 11.0 DA: *
G 191-B2B 05 05 30.6119 +52 49 51.945 11.79 DAw... *
G 93-48 21 52 25.3835 +02 23 19.556 12.73 DA
Gamma UMa 11 53 49.8475 +53 41 41.136 2.427 A0V
GD 108 10 00 47 -07 33.5 13.56 B *
GD 50 03 48 50.10 -00 58 28.5 13.98 DAw...
GRW+70 5824 13 38 50.4743 +70 17 07.619 12.80 DA: *
HD 49798 06 48 04.6995 -44 18 58.431 8.27 sdO6p
HD 60753 07 33 27.3188 -50 35 03.319 6.682 B2III
HD 93521 10 48 23.5112 +37 34 13.090 7.06 O9Vp *
HZ 21 12 13 56.27 +32 56 31.4 14.22 DA: *
HZ 2 04 12 43.49 +11 51 50.6 13.86 DA:
HZ 44 13 23 35.258 +36 07 59.51 11.3 B2 *
HZ 4 03 55 21.77 +09 47 18.4 14.47 DA: *
LB 227 04 09 28.50 +17 07 55.2 15.35 DA
LDS 749B 21 32 16.1 +00 15 15 14.58 DB
Mu Col 05 45 59.8950 -32 18 23.166 5.148 O9.5V
NGC 7293 22 29 48.4 -20 49 26 13.54 *
Zeta Cas 00 36 58.2846 +53 53 48.874 3.666 B2IV


References