Spectrophotometric Standards - II
(ING Technical
Note 100)
ING Technical Note 65 gave information on 59 Spectrophotometric Standards. A further list, including fainter standards, is presented here. Positions accurate to 1 arcsecond are given for all stars in the list. All the positions are given to equinox J2000.0. Where proper motions are known, positions are given for epoch J2000.0; otherwise the epoch is that of the Palomar Observatory Sky Survey (POSS) plate on which the position was measured. A plot of flux distribution and an identification chart are given for each standard.
Introduction:
This Technical Note has been compiled primarily for observers requiring
a quick-reference list of stars which can be used for flux calibration
purposes.
The flux data are obtained from Massey (1988) and Oke (1990).
The data from Massey cover the range 3200 to 8100 Å at intervals
of 50 Å, and that from Oke 3200 to 9200 Å, with the range
3200 to 4700 given in 1 Å intervals and 4700 to 9200 at 2 Å.
Apart from the newly derived positions, all the data given are gathered
from other sources and the original references should be consulted for
detailed information regarding instruments used, observational
techniques and estimates of precision.
Contents:
Summary data for all the stars in the list are gathered in the
Table.
In addition to the star name the table contains:
accurate equatorial coordinates and proper motions;
an indication of visual magnitude;
a spectral type and
the local ING Name by which the star is known to the La Palma
computers at the Isaac Newton Group of telescopes.
The main body of the Technical Note consists of data sheets for the
standards, set out in order of right ascension with one star per page.
Each page is identified, in the top right-hand corner, by the ING
Name of the standard star.
There is also a finding chart produced using the Digitized Sky Survey
from the Space Telescope Science Institute, and a plot of the
flux distribution.
If a standard has been observed by both Massey and Oke, plots using
both sources of data are given.
Star names:
The names of most relevance to observers visiting La Palma will be
those by which the stars are known to the control computers of the
various telescopes.
The names are constructed using the letters SP (to indicate that
they refer to spectrophotometric standards) together with a designation
(based on its B1950 position) following the IAU convention for the
naming of astronomical sources.
Using this name at the WHT, or in a control file, ensures that
the telescope will set directly on the correct position at the date of
the observation, without the observer having to be concerned with the
proper motion or precession.
On the INT the positions are held in the catalogue SPECPHOT, together
with the positions from TN 65.
Positions:
As stated in TN 65, since modern telescopes have the capability
of setting very accurately, accurate positions should be provided
to make efficient use of telescope time.
Any star in this list which did not have a measured position accurate
to 1 arcsec was re-measured from the POSS copy plates using either
a PDS or a Coradograph measuring machine.
Each standard was referred to 8-10 nearby PPM reference stars.
The star positions held in the system catalogues on the control
computers will be edited when improved positions appear for any of
the stars, so will not necessarily agree exactly with those in this note.
Proper motions:
All proper motion catalogues available were searched for relevant entries.
Some of the standards appear in lists published by Giclas in
various Lowell Observatory Bulletins, or the proper
motion catalogues of Luyten, published by the University of Minnesota.
Their proper motions have been adopted here except where given in
the Carlsberg Meridian Catalogues (CMC).
Magnitudes and spectral types:
The magnitudes and spectral types given in the table
are all taken from the papers in which the relevant spectrophotometry
appear.
The magnitude given is intended to give an approximate `visual'
magnitude for identification and planning purposes.
The magnitude for stars from the Massey (1988) publication
are m5556, and those from OKE are m5460.
The spectral types are intended to give a broad idea of the overall
light distribution, so that a suitable object can be selected for
the required purpose.
Charts:
The identification charts were made using the Digitized Sky Survey
from the Space Telescope Science Institute.
Each chart is centred on the J2000.0 position of the standard.
If a star has a large proper motion, and the epoch of the chart
is not close to 2000.0, then the star appears off-centre.
The epochs of the charts vary between 1949 and 1985 and each one
is labelled.
For any star with a known proper motion the chart is
accompanied by a simple line drawing showing the magnitude and
direction of fifty years' proper motion to the same scale as the
chart.
Flux distributions:
The spectrophotometry of the standards has been taken from the sources
indicated in the notes to the Table.
The plots of flux distribution were made using data from the
original publications, or in the case of the Oke data,
from files available on the Starlink STADAT computer at RAL.
These files are in the directory:
Directory STADAT::SPECTRAL_ATLASROOT:[OKE]
| AAAREADME.OKE;5 | BDP254655.TAB;2 | BDP254655A.TAB;2 | BDP284211.TAB;2 |
| BDP284211A.TAB;2 | BDP332642.TAB;2 | BDP332642A.TAB;2 | BDP75325.TAB;2 |
| BDP75325A.TAB;2 | FEIGE110.TAB;2 | FEIGE110A.TAB;2 | FEIGE34.TAB;2 |
| FEIGE34A.TAB;2 | FEIGE66.TAB;2 | FEIGE66A.TAB;2 | FEIGE67.TAB;2 |
| FEIGE67A.TAB;2 | G138M31.TAB;2 | G138M31A.TAB;2 | G158M100.TAB;2 |
| G158M100A.TAB;2 | G191B2B.TAB;2 | G191B2BA.TAB;2 | G193M74.TAB;2 |
| G193M74A.TAB;2 | G24M9.TAB;2 | G24M9A.TAB;2 | G60M54.TAB;2 |
| G60M54A.TAB;2 | GD108.TAB;2 | GD108A.TAB;2 | GD248.TAB;2 |
| GD248A.TAB;2 | GD50.TAB;2 | GD50A.TAB;2 | GRWP705824.TAB;2 |
| GRWP705824A.TAB;2 | HD93521.TAB;2 | HD93521A.TAB;2 | HZ21.TAB;2 |
| HZ21A.TAB;2 | HZ4.TAB;2 | HZ44.TAB;2 | HZ44A.TAB;2 |
| HZ4A.TAB;2 | LTT9491.TAB;2 | LTT9491A.TAB;2 | NGC7293.TAB;4 |
| NGC7293A.TAB;4 | SA95M42.TAB;2 | SA95M42A.TAB;2 |
I have typed in the Massey data from the publication.
The files are held together with the Oke standards
in the anonymous FTP account
ftp.ast.cam.ac.uk, in subdirectory pub/fluxstds.
They are also available from the RGO www page, in
the LPINFO Calibration section.
WWW Address http://www.ast.cam.ac.uk/%7Ejes/index.html.
If anyone has any trouble accessing them, I could email the
flux values for any of the standards in this note.
jes@ast.cam.ac.uk
References
CMC, (1-8), 1984-1993. Copenhagen University Observatory,
Royal Greenwich Observatory, and the Real Instituto Observatorio de
la Armada en San Fernando.
Giclas, H.L., 1963. Lowell Obs. Bull. No. 120.
Luyten, W.J., 1944. Pub. Univ. Obs. Minnesota III No. 4.
Luyten, W.J., 1961. Catalogue of 7127 Stars in the Northern Hemisphere
with Proper Motions Exceeding 0.2 arcseconds
Annually, Lund Press, Minneapolis, Minn. [`LTT']
Massey, P., Strobel, K., Barnes, J.V., & Anderson, E. 1988,
Astrophys. J. 328, 328.
Oke, J.B., 1990, Astron. J., 99, 1621.
PPM Star Catalogue, 1991-1993, Röser, S. & Bastian, U.,
Astronomische Rechen-Institut, Heidelberg.
Sinclair, J.E. & Wood, R. 1989,
ING La Palma Technical Note No. 65
Table 1 TN 100
Spectrophometric Standards referred to equinox J2000.0
Original RA Dec Proper m5556 ST ING Name Note
Name motion
G 158-100 00 33 54.5 -12 07 58 +0.011 -0.17 14.82 sdG SP0031-124 2,3
PG0205+134 02 08 03.4 +13 36 25 14.87 sdOB SP0205+134 1
PG0216+032 02 19 18.8 +03 26 54 14.79 sdOC SP0216+032 1
PG0310+149 03 13 37.2 +15 06 22 15.63 sdO SP0310+149 1
GD 50 03 48 50.0 -00 58 32 +0.002 -0.15 14.06 DA2 SP0346-011 2
SA95-42 03 53 43.7 -00 04 29 15.60 SP0351-002 2
HZ 4 03 55 22.0 +09 47 19 +0.012 0.0 14.47 DA SP0352+096 2,3
HZ 14 04 41 01.8 +10 59 41 +0.007 +0.01 14.01 DA SP0438+108 1,3
G 191-B2B 05 05 30.6 +52 49 56 +0.004 -0.09 11.85 DA0 SP0501+527 1,2,3
Hiltner 600 06 45 13.4 +02 08 15 10.42 B1V SP0642+021 1,3
G 193-74 07 53 27.2 +52 29 31 -0.008 -0.26 15.58 DC SP0749+526 2
BD+75o 325 08 10 49.2 +74 57 57 -0.002 -0.01 9.52 O5p SP0804+751 2
PG0823+546 08 26 49.4 +54 28 01 14.36 sdOC SP0823+546 1
PG0846+249 08 49 05.9 +24 45 08 16.94 DA1 SP0846+249 1
PG0934+554 09 38 20.4 +55 05 54 +0.002 -0.04 12.16 sdO SP0934+554 1,4,5
PG0939+262 09 42 50.8 +26 01 01 14.89 DA1 SP0939+262 1
GD 108 10 00 47.2 -07 33 31 -0.003 0.00 13.57 sdB? SP0958-073 2,5
Feige 34 10 39 36.7 +43 06 10 11.25 sdO SP1036+433 1,2,3,5
HD93521 10 48 23.5 +37 34 13 0.000 +0.01 6.96 O9Vp SP1045+378 2,5
PG1121+145 11 24 15.1 +14 13 46 16.97 DA1 SP1121+145 1
GD 140 11 37 05.1 +29 47 58 -0.012 -0.01 12.50 DAn SP1134+300 1,3,5
EG 81 11 37 26.4 +14 10 15 -0.006 -0.05 13.30 sdO SP1134+144 1
HZ 21 12 13 56.6 +32 56 30 14.67 DO2 SP1211+332 2
Feige 66 12 37 23.6 +25 03 59 0.000 -0.03 10.54 sdO SP1234+254 1,2
Feige 67 12 41 51.8 +17 31 21 11.89 sdO SP1239+178 1,2
G60-54 13 00 09.0 +03 28 38 -0.026 -0.92 15.73 DC SP1257+038 2
HZ 44 13 23 35.3 +36 08 01 -0.004 +0.03 11.74 sdO SP1321+363 1,2,3
Grw+70 5824 13 38 52.8 +70 17 08 -0.027 -0.02 12.72 DA SP1337+705 2,3
PG1545+035 15 48 24.2 +03 22 51 14.34 sdOB SP1545+035 1
BD33 2642 15 51 59.9 +32 56 53 10.74 B2IVp SP1550+330 2,3
G 138-31 16 27 53.4 +09 12 16 -0.007 -0.46 16.07 DA7 SP1625+093 2,3
PG1708+602 17 09 15.9 +60 10 10 13.92 sdOC SP1708+602 1
HD 192281 20 12 33.2 +40 16 06 -0.001 +0.02 7.44 O5f SP2010+401 1
G 24-9 20 13 55.7 +06 42 45 -0.017 -0.58 15.77 DQ7 SP2011+065 2,3
Cyg Ob2-9 20 33 10.8 +41 15 09 10.70 O5If SP2031+410 1
Wolf 1346 20 34 21.9 +25 03 51 -0.030 -0.55 11.59 DA SP2032+248 1,3
BD+28 4211 21 51 11.1 +28 51 53 10.56 sdOp SP2148+286 1,2,3
BD+25 4655 21 59 41.9 +26 25 57 -0.002 -0.05 9.65 SP2157+261 2
NGC 7293 22 29 38.4 -20 50 14 13.48 SP2226-210 2
HD 217086 22 56 47.1 +62 43 38 +0.000 -0.01 7.49 O5 SP2254+624 1
LTT 9491 23 19 34.6 -17 05 29 +0.018 +0.04 14.06 DC SP2316-173 2
Feige 110 23 19 58.4 -05 09 57 11.88 DOp SP2317-054 1,2,3,5
GD 248 23 26 06.5 +16 00 21 -0.003 -0.09 15.08 DQ5? SP2323+157 2,3
1: Massey,P., Strobel,K., Barnes,J.V & Anderson,E., 1988, Ap. J.,328, 315.
2: Oke,J.B., 1990, Astron. J. 99, 1621.
3: Sinclair, J.E. & Wood, R., 1989. ING Technical Note, No. 65.
4: Alias GD 299. Magnitude given is mv
5: Positions and proper motions from CMC