New and unpublished photometric data of HD 45677 in the Walraven WULBV,
Strömgren uvby, Johnson/Cousins 
and ESO JHKLM system are
listed in an accompanying paper
(de Winter et al. 1996; Paper I) and will be
analyzed and discussed in this paper.
Several new low resolution CCD spectra of HD 45677 were taken at La Silla
using the Boller and Chivens spectrograph mounted on the ESO 1.52 m telescope.
Details of the observations are given in Table 1 (click here).
In order to get a sufficiently good
S/N for weaker emission lines it was necessary to have the strength of
H
exceed the CCD saturation limit. To be able to measure the relative
strength of H
second, shorter, exposures during the same two December
nights were taken in which H
was not saturated.
A combined spectrum of the 1992 d, e, f and 1992 g spectra is presented in
Fig. 4 (click here).
Table 1: Log of published and newly taken optical
spectroscopic observations of HD 45677
To reveal the H
profile and to test for short time scale variations
two intermediate resolution spectra, Fig. 5 (click here), centered around H
, were
obtained. These observations, see Table 1 (click here), were made
with the Boller and Chivens spectrograph mounted
on the ESO 1.52 m telescope at La Silla.
The detector for all the low and intermediate resolutions taken spectra
was a Ford Aerospace 2048
2048 pixel CCD,
with a 15
15 
m pixel size.
To detect short time scale variations, HD 45677 was followed day to day
between the 8
and the 14
of October 1993 by
using the CAT/CES combination at La Silla.
This combination was used to obtain high resolution spectra in the H
and NaID wavelength ranges, which are presented in Figs. 9 and
10. Further high resolution spectra, in the H
, CaIIK, and
[OI] 6300 Å wavelength ranges (Figs. 6-8),
were obtained in January 1994. During all observations, the detector was a
1024 
640 RCA SID 006 high resolution CCD, with a pixel size of
15
15 
m. All the CAT/CES observations were controlled
remotely from ESO Headquarters, Garching bei München, Germany.
All spectra were reduced using the MIDAS software running under SUN/OS at ESO headquarters. For optimal extraction of spectral data from the CCD images the optimal extraction algorithm by Horne (1986) was applied. After reduction, the low-resolution spectra were combined into one single, completely unsaturated, spectrum, with spectrophotometric quality. The new spectral data are shown in Figs. 4-10. Additional details of all spectroscopic observations are listed in Table 1 (click here).
Images of HD 45677 were obtained, under reasonable (1
1-1
6)
seeing conditions, with the Dutch 92 cm telescope at La Silla. Two observing
runs were used, on the 10
and 14
of February 1993, and
on the 7
of August 1993.
The images were reduced using MIDAS, running on a VAX cluster at the
University of Amsterdam. On all of the images, taken through B, V, R,
Gunn i, Gunn z, wideband H
, narrowband H
and narrowband
[OI]
6300 filters, HD 45677 was indistinguishable from a
stellar point source. No nebulosity of emission or reflection nature were
visible. By checking POSS (Palomar Observatory Sky Survey) plates, searching
for significant changes of the number of stellar objects in the surroundings
of HD 45677, no dark region could be marked.
Figure 1: Light curve of HD 45677. a) Using photographic and photoelectric
data from 1899 to 1994. b) Using photoelectric data from 1971 to 1994. The
labels A - E denote the different datasets discussed in Sects. 3.2 and 3.3
