The Maitzen photometric system
Basic Reference
Maitzen H.M. 1976, Astron. Astrophys. 51, 223
Abstract
For a statistical investigation of the broad-band flux depression in the
visible spectra of Ap and related stars, a five filter photometric system
was used conatining Strögren vby and two intermediate band
filters g1 at lambda 5020 Å and g2 at lambda 5240
Å. Three indices were observed for 93 Ap, 23 Am 8 Hg-Mn and 57 normal
A stars (9 of this sample are members of the Ap rich open cluster NGC 2516).
(b-y) as temperature indicator, m1 as lambda 4100 Å
depression parameter and a1 = g2 - (g1 + y) / 2 which is proposed as new
photometric index for the flux depression at lambda 5200 Å. It is shown
that a can be neasured with higher accuracy than the other parameters
and that it is possible to assign Ap character to stars with excess values
in a (compared to a-values of normal A stars). Contrary
to m1 the a-values of Am and Hg-Mn stars are essentially
normal. Virtually all Ap stars with (b-y) < 0.1 have peculiar
a-values.
Content
Access to the data and references
Asiago Database on Photometric System (ADPS)
Indices and Parameters
a, Da, Da0
Filters
g1 and g2 are Schott (IL) interference filters
The parameters are defined by :
- a = g2 - (g1 + y) / 2
- Delta a = a - a0
where a0 = a0(b-y) for normal stars.
Photomultiplier
EMI 6256, EMI 9502
Please, send your
commentsto epaunzen@physics.muni.cz
epaunzen@physics.muni.cz
Last update: 2 April 1998
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