2 Observations

2.1 Photometry

The RS CVn type eclipsing binary MM Herculis was observed in B, V and R filters of the UBV system on 42 nights from May 5th to October 8th in 1998 and on 45 nights from March 1st to October 6th in 1999 at the Ege University Observatory. A total of 749 and 912 observational points were obtained in each colour in 1998 and 1999, respectively. The observations were made with the 48-cm Cassegrain telescope to which an SSP5A type photometer, including an unrefrigerated Hamamatsu R4457 PMT, was attached. The stars BD +21$^\circ$3274 and BD +22$^\circ$3250 were taken as comparison and check stars, respectively. The differential magnitudes, in the sense of variable minus comparison, were corrected for atmospheric extinction and the observed times were reduced to the Sun's center. No variability in the light of the comparison star was detected. Later on the brightness and colour of the comparison star were transformed to the standard system and these standard values have been given in Paper I. The standard deviation of each observed point is approximately  $\pm0\hbox{$.\!\!^{\rm m}$ }005$. The new light elements of the system have been taken from Tas (2000b) as:

$${\rm Min~I}={\rm JD(Hel)}\,\, 2\,445\,551.4274+7\hbox{$.\!\!^{\rm d}$ }960326~E.$$ (1)

The cooler and more massive component of MM Her is at the inferior conjunction (closer to the observer) at phase zero. These elements have been used in all the calculations pertaining to the observations. The nightly mean magnitudes and colours obtained outside eclipses from 1998 to 1999 are given in Table 1. There are 33 and 28 observing nights outside eclipses in 1998 and 1999, respectively. In this table the columns present heliocentric time, phase, magnitude in V, colour in B-V and V-R. The standard deviation of each measurement was also given in this table.

Figure 1: The light and colour (B-V and V-R) variations outside eclipses for 1998.

Figure 2: The same as in Fig. 1, but for 1999.

 

 

Table 1: The nightly mean magnitudes and colour of MM Her for 1998 and 1999.

1998					1999
HJD	Phase	V	B-V	V-R	HJD	Phase	V	B-V	V-R
(2400000+)		(mag)	(mag)	(mag)	(2400000+)		(mag)	(mag)	(mag)
50939.4210	0.8559	$9.497 \pm 007$	$0.876 \pm 010$	$0.658 \pm 011$	51239.5278	0.5562	$9.498 \pm 014$	$0.869 \pm 024$	$0.663 \pm 013$
50949.4271	0.1129	$9.509 \pm 007$	$0.871 \pm 033$	$0.633 \pm 007$	51250.5293	0.9382	$9.503 \pm 007$	$0.858 \pm 015$	$0.650 \pm 016$
50941.4296	0.1082	$9.523 \pm 007$	$0.868 \pm 014$	$0.651 \pm 011$	51240.5429	0.6837	$9.500 \pm 009$	$0.869 \pm 024$	$0.663 \pm 013$
50949.4271	0.1129	$9.509 \pm 007$	$0.871 \pm 033$	$0.633 \pm 007$	51250.5293	0.9382	$9.503 \pm 007$	$0.871 \pm 018$	$0.654 \pm 019$
50955.5042	0.8763	$9.510 \pm 016$	$0.865 \pm 016$	$0.664 \pm 016$	51313.3763	0.8333	$9.481 \pm 010$	$0.869 \pm 019$	$0.660 \pm 009$
50951.4458	0.3665	$9.503 \pm 011$	$0.870 \pm 013$	$0.668 \pm 016$	51290.3979	0.9467	$9.503 \pm 021$	$0.853 \pm 007$	$0.668 \pm 022$
50954.4756	0.7471	$9.499 \pm 014$	$0.873 \pm 026$	$0.657 \pm 014$	51295.4038	0.5755	$9.491 \pm 011$	$0.867 \pm 015$	$0.654 \pm 019$
50955.5042	0.8763	$9.510 \pm 016$	$0.865 \pm 016$	$0.664 \pm 016$	51313.3763	0.8333	$9.481 \pm 010$	$0.869 \pm 019$	$0.656 \pm 017$
50957.4255	0.1177	$9.521 \pm 014$	$0.861 \pm 016$	$0.656 \pm 010$	51325.3889	0.3423	$9.505 \pm 011$	$0.883 \pm 020$	$0.661 \pm 013$
50958.4144	0.2419	$9.510 \pm 011$	$0.869 \pm 018$	$0.653 \pm 013$	51327.3879	0.5935	$9.495 \pm 013$	$0.882 \pm 012$	$0.661 \pm 013$
50967.3644	0.3662	$9.504 \pm 006$	$0.876 \pm 011$	$0.669 \pm 007$	51339.3985	0.1023	$9.522 \pm 008$	$0.873 \pm 023$	$0.658 \pm 015$
50962.4169	0.7447	$9.487 \pm 014$	$0.881 \pm 020$	$0.659 \pm 015$	51332.2220	0.2007	$9.520 \pm 008$	$0.882 \pm 012$	$0.661 \pm 013$
50967.3644	0.3662	$9.504 \pm 006$	$0.876 \pm 011$	$0.669 \pm 007$	51339.3985	0.1023	$9.522 \pm 008$	$0.874 \pm 013$	$0.650 \pm 011$
50970.4063	0.7484	$9.493 \pm 008$	$0.876 \pm 016$	$0.651 \pm 010$	51342.3246	0.4698	$9.511 \pm 013$	$0.871 \pm 019$	$0.661 \pm 017$
50974.3519	0.2441	$9.514 \pm 015$	$0.868 \pm 039$	$0.657 \pm 008$	51348.4331	0.2372	$9.516 \pm 008$	$0.884 \pm 012$	$0.663 \pm 013$
50977.4044	0.6275	$9.501 \pm 011$	$0.883 \pm 015$	$0.657 \pm 012$	51369.3630	0.8665	$9.519 \pm 010$	$0.874 \pm 019$	$0.652 \pm 019$
50979.4068	0.8790	$9.499 \pm 010$	$0.874 \pm 016$	$0.653 \pm 009$	51372.4189	0.2504	$9.514 \pm 006$	$0.876 \pm 023$	$0.661 \pm 008$
50982.3771	0.2522	$9.507 \pm 014$	$0.866 \pm 019$	$0.651 \pm 013$	51376.3977	0.7502	$9.484 \pm 010$	$0.890 \pm 028$	$0.666 \pm 021$
50989.3485	0.1279	$9.523 \pm 013$	$0.869 \pm 020$	$0.648 \pm 015$	51379.4154	0.1293	$9.535 \pm 010$	$0.868 \pm 022$	$0.661 \pm 013$
51001.3352	0.6337	$9.511 \pm 013$	$0.889 \pm 019$	$0.670 \pm 020$	51381.4044	0.3792	$9.518 \pm 010$	$0.886 \pm 017$	$0.662 \pm 014$
51010.3256	0.7632	$9.492 \pm 008$	$0.873 \pm 016$	$0.653 \pm 008$	51388.3567	0.2526	$9.507 \pm 013$	$0.894 \pm 017$	$0.650 \pm 014$
51015.3367	0.3927	$9.490 \pm 015$	$0.873 \pm 017$	$0.656 \pm 016$	51407.3052	0.6329	$9.490 \pm 010$	$0.885 \pm 016$	$0.663 \pm 015$
51017.3324	0.6434	$9.491 \pm 009$	$0.886 \pm 017$	$0.649 \pm 009$	51411.3788	0.1447	$9.541 \pm 015$	$0.869 \pm 028$	$0.659 \pm 015$
51019.3740	0.8998	$9.506 \pm 006$	$0.866 \pm 032$	$0.649 \pm 011$	51415.3030	0.6374	$9.487 \pm 014$	$0.885 \pm 030$	$0.657 \pm 018$
51027.3169	0.8976	$9.499 \pm 018$	$0.861 \pm 023$	$0.641 \pm 015$	51421.2948	0.3905	$9.511 \pm 015$	$0.882 \pm 020$	$0.661 \pm 016$
51040.3382	0.5334	$9.496 \pm 012$	$0.886 \pm 017$	$0.656 \pm 010$	51427.2617	0.1397	$9.547 \pm 010$	$0.870 \pm 025$	$0.667 \pm 008$
51052.2745	0.0329	$9.524 \pm 011$	$0.868 \pm 015$	$0.665 \pm 014$	51443.2350	0.1463	$9.535 \pm 005$	$0.863 \pm 023$	$0.653 \pm 008$
51073.3145	0.6760	$9.493 \pm 008$	$0.868 \pm 021$	$0.652 \pm 013$	51445.2716	0.4024	$9.522 \pm 011$	$0.879 \pm 020$	$0.672 \pm 013$
51075.2527	0.9195	$9.510 \pm 019$	$0.853 \pm 029$	$0.658 \pm 018$	51446.3100	0.5330	$9.510 \pm 012$	$0.880 \pm 016$	$0.660 \pm 015$
51080.2899	0.5523	$9.484 \pm 018$	$0.890 \pm 018$	$0.653 \pm 014$	51449.2513	0.9020	$9.526 \pm 010$	$0.859 \pm 016$	$0.664 \pm 018$
51081.2970	0.6788	$9.493 \pm 020$	$0.878 \pm 053$	$0.658 \pm 030$	51456.2300	0.7790	$9.505 \pm 008$	$0.878 \pm 014$	$0.654 \pm 015$
51084.2287	0.0471	$9.526 \pm 008$	$0.872 \pm 008$	$0.664 \pm 010$
51092.3013	0.0612	$9.525 \pm 006$	$0.866 \pm 005$	$0.656 \pm 010$
51093.2442	0.1796	$9.524 \pm 010$	$0.874 \pm 011$	$0.664 \pm 009$
51094.2475	0.3057	$9.498 \pm 012$	$0.876 \pm 029$	$0.661 \pm 015$
51095.2292	0.4290	$9.486 \pm 004$	$0.871 \pm 014$	$0.651 \pm 014$

2.2 Spectroscopy

Figure 3: The migration curves of the spots.

The spectroscopic observations were carried out between July 19 and 30, 1999 and between August 16 and September 5, 1999 at Catania Astrophysical Observatory (Mt. Etna, Italy) with the REOSC echelle spectrograph fed by the 91-cm telescope through an UV-NIR fiber of 200$~\mu$m core diameter. High-resolution spectroscopy was obtained by using the echelle cross-dispersion configuration based on a 900 lines/mm echellette grating and an echelle grating with 79 lines/mm.

The data were acquired with a $1100\times 1100$ SITe thinned back-illuminated CCD of $24\times 24~\mu$m pixel size, yielding a spectral range (in 5 orders) of approximately 5860 Å to 6700 Å, and a dispersion of 0.16 Å per pixel. For all observing runs the width of the slit was set to be 550 $\mu$m, projected onto 2.7 pixels of the detector, providing a spectral resolving power $\lambda$/$\Delta$$\lambda$ = 14000. The signal-to-noise ratio (S/N) achieved is between 30 and 50, depending on atmospheric condition.

Sixteen spectra of MM Her were collected during 11 observing nights. We used 51 Peg (G2.5 IV) and $\delta$ Eri (K0 IV) as standard stars for hotter and cooler component, respectively. Typical exposure times for the MM Her spectroscopic observations were 3600 and 4200 s. $\alpha$ Ari was observed as a radial-velocity standard star.

The reduction of data including bias, scattered light and flat field corrections, extraction of spectral orders and wavelength calibration was performed on the raw images with Image Reduction and Analysis Facilities (IRAF) distributed by NOAO. For the wavelength calibration the emission lines of a Th-Ar lamp were used.