I N T R O D U C T I O N The DPR gives various kinds of daily data for the positions and areas of sunspots, including all sunspot groups that could be seen at least on two days. All spots, even the very small ones, have been separately measured in Debrecen and in the catalogue the results of measurements are given singly or jointly, whichever is reasonable, in each case with almost full particulars. Since nowadays it is understood that a sunspot group is essentially a magnetic system, therefore the DPR also indicates for each sunspot its magnetic polarity. All sunspot groups should be considered as being made up of one or several bipolar spot pairs. This is why we always try to find out the bipolar pairs of individual spots and to identify the spots one by one mainly by means of variation of their Carrington coordinates from day to day. The evolution of a sunspot group, i.e. its development and decay can be easily followed making use of the detailed data of our DPR catalogue. MATERIAL OF OBSERVATIONS 365 "white-light" photoheliograms for the year 1977, obtained 97 in Debrecen (before June 23), 193 in Gyula (at our observing station, after May 3), 68 at the Kislovodsk Observatory, 5 at the Kodaikanal observatory and 2 at the Observatorio del Ebro were used one for each day. The 290 Debrecen and Gyula heliograms were selected from more than 4000 heliograms, using the best from each day, and at least a second one was also measured, as a check-test. In addition, 63 extra heliograms obtained at the co-operating observatories on the same days when we also had our own observation were used as a control. Magnetic polarities determined at the Mount Wilson and the Yunnan observatories were principally used. In 1977 they had observations at Mount Wilson on 273 days and at Yunnan on 218 days. We used the copies of the original observations, i.e. the sunspot polarity drawings of Mt.Wilson and Yunnan. In addition, we also took into consideration some published data, e.g. Rome observations for the second half of 1977 (Oss.Astr.Roma, Monthly Bull. Nos.233-236) and the Russian Magn.Polya Soln.Pyaten (Suppl.to Soln. Dan.Byull.) for the year 1977. A c k n o w l e d g e m e n t s are due to all observers: A.Kovacs, L.Gesztelyi, A.Ludmany, B.Kalman, O.Gerlei and G.Gyertyanos in Debrecen; L.Gyori, L.Marki-Zay, S.Rostas, Z.Kiss and L.Kondas in Gyula; V.V.Makarova and V.P.Mikhailutsa at Kislovodsk and at Ebro the observer-in- charge was Jose Cid; T.S.Gregory, T.B.Ake and S.P.Padilla at Mt. Wilson; Ding You-ji, Zhang Heng, Zhong Shu-hua, Lung Ti, Ye Hui-lian and Zhong Ling-sheng at Yunnan. We owe particular debt of gratitude to Zhong Shu-hua who kindly prepared for us duplicates of the polarity records of Yunnan. First and foremost we are indebted to the leading scientists M.N.Gnevyshev and V.I.Makarov, the late M.K.Vainu Bappu, J.O.Cardus, R.F.Howard and You-ji Ding,who were associated with the observatories of Kislovodsk, Kodaikanal, Ebro, Mt.Wilson and Yunnan, respectively, for arranging for us the possibility to use their material of observations. OBSERVATIONS In the beginning of 1977 in Gyula, at the top of a 40 m high water tower, the heliograph got new equatorial mounting and a renovated massive platform with a grid floor allowing the free circulation of air. The construction of a new platform of observation for the Debrecen heliograph started only in the middle of 1977 and from this time onward no white-light heliograms were obtained in Debrecen for a long time. In Debrecen and in Gyula fairly similar photoheliographs were used and both objectives of about 14 cm (2 m focal length) were generally stopped down to 13 cm in Debrecen and to 7-8 cm (sometimes only to 9 cm) in Gyula to take solar images of about 11 cm and 10.4 cm through yellow filters mainly on Gevaert plates and Kodalith films, respectively. (Cf. DPR 1977,pp.13-14) At Kislovodsk a heliograph of Maksutov-type was used. The 13 cm aperture was mostly stopped down to 5 cm to take solar images of 8 cm without any filter. At Kodaikanal the objective aperture was 15 cm and the diameter of the solar image was about 19 cm. At Ebro the diameter of the solar image was about 10 cm. (Cf. DPR 1977,pp.27-28.) The geographic positions of the observatories are as follows: LONGITUDE LATITUDE ALTITUDE East of Greenwich North above see level h m s deg arcmin m Ebro 0 01 58 40 49.2 50 Gyula 1 25 05 46 39.2 135 Debrecen 1 26 29 47 33.6 135 Kislovodsk 2 50 07 43 44.0 2130 Kodaikanal 5 09 52 10 13.8 2343 INSTRUMENTAL CONSTANTS (Cf. DPR 1977,pp.15-21.) The photoplate should be perpendicular to the optical axis. In 1977 for both heliographs of German mounting the deviation from this perpendicularity, i.e. the inclination and its position angle were determined from differences of spot positions, measured on pairs of plates taken in principle at the same time, in practice within some minutes on both (east and west) sides of the pillar. At the Debrecen and Gyula heliographs for the inclinations 0.76 and 0.33 deg, while for the position angles 185 and 120 deg were found by means of 111 and 171 spot pairs, respectively. The distortion of the magnifying lens system has been determined for both of our heliographs by means of an adequate distortion target and the relevant values (given in DPR 1977,p.21) have been used. ORIENTATION OF THE HELIOGRAMS (Cf. DPR 1977,pp.22-27) For orientation a cross-hairs of spider-wires are used, their point of intersection is at the optical axis, and one of the spider-wire is directed roughly north-south. In order to determine the exact north-south direction, so-called zero heliograms were taken (exposed twice with an interval of about 90 seconds between the two exposures, while the heliograph being firmly clamped). In the two overlapping images of the Sun the angle between the line joining the points of intersections of the two solar limbs and the north-south spider-wire, i.e. the "zero position angle" is measured. Corrections have been applied for variation in the Sun's declination, for the slight convergence of the relevant meridians and for variation as a consequence of atmospheric refraction. For each "undisturbed" period the most probable values of the zero position angle as a function of the hour angle were estimated with a curve by a graphic method. During 1977 in Debrecen and Gyula 280 and 478 zero heliograms were obtained on 87 and 63 days (in the periods of Jan 1 - Jun 22 and May 4 - Dec 31), respectively. In Debrecen the zero position angle was almost stable (in spite of the fact that on March 4 there was a small earthquake). In Gyula after the new mounting of the heliograph, in the first month the zero position angle was constant, however, later on some gradual changes were noticed, which were due to a change in inclination of the polar axis of the equatorial and this was taken into consideration. In case of the foreign heliograms the 63 extra plates, mentioned above, were used to control the orientation i.e. from the differences in the positions measured on both the foreign and our heliograms, taken on the same day, the adequate value of the zero position angle could be deduced (cf. DPR 1977,p.28). MEASUREMENTS (Cf. DPR 1977,pp.29-30) All position measurements were carried out by means of an ASCORECORD coordinate measuring instrument by A.Kovacs. Rectangular coordinates x, y were directly recorded. First of all the centre of the cross-wires and at least 8 points along the limb of the Sun's disc were measured (the 4 intersections of the perpendicular cross-wires with the limb and another 4, at the ends of the vertical and horizontal solar diameters for determining the actual differential refraction at the moment of observation). The position of the centre of each umbra in every sunspot was measured one by one, considering even any tiny dark core if it is quite alone in a penumbra. In all those cases where it was not possible to see any umbra in a sunspot the position of the geometrical centre of the spot was measured for each spot, also one by one. (Exceptions were taken only in cases of two or three very little close spots.) Furthermore not only the well separated umbrae or spots but even those temporarily bordered on were measured one after the other. The sunspot areas were determined by O.Gerlei with our special area measuring instrument (DAREAL) using video facilities . (Cf.DPR 1977, Appendix 2,pp.219-230) In all cases where the positions were previously recorded, both the umbra and the whole spot (umbra+penumbra) area were measured directly in the photoheliograms. By using the actual predetermined radius of the solar image we got the Projected Areas expressed in millionth of the Sun's apparent disc. The Projected Area multiplied by 0.5*sec(rho), where "rho" is the relevant angular distance from the centre of the apparent solar disc as viewed from the Sun's centre, is the Corrected Area, i.e. the area corrected for geometrical foreshortening, expressed in millionths of the Sun's visible hemisphere. REDUCTION OF THE COORDINATES The heliographic coordinates were calculated from each measured x, y coordinates, as given in DPR 1977,pp.31-35. The calculations were performed by a PDP 11/40 computer of the Institute of Nuclear Research of the Hungarian Academy of Sciences in Debrecen. (From these positions all final data published in DPR 1977 were calculated by a small programmable pocket calculator.) In 1977 there were used 21 heliograms obtained at an altitude of 11 deg above the horizon, or at lower altitudes (the lowest was 5.6 deg). All of them were taken at Kislovodsk in winter-time. The principal data for physical observation of the Sun are taken from The Astronomical Ephemeris for the year 1977 (H.M.Stationary Office, London, 1975). The longitude of the ascending node of the solar equator on the ecliptic for 1977.0 was 75 deg 26.4 arcmin.