COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS NUMBER 358 Konkoly Observatory Budapest 1969 June 24 PROPERTIES OF THE OPTICAL RADIATION OF NOVAE AND SUPERNOVAE STARS It was noticed that the relations between V,B or U,B photoelectric magnitudes can be described by linear regressive correlations for intrinsic variables of different types. The gradients DeltaV/DeltaB and DeltaU/DeltaB can be considered as quantitive characteristics of optical radiation properties when DeltaV is not very small (>0.5m). They reveal the process of variability in its development. The changes of UBV magnitudes are plotted for four novae and four supernovae stars according to series of photoelectric observations with DeltaV > 0.5m. The errors of gradients are smaller than 0,03 in all the cases. The N Her 1963 observations in (3,4,5) comprise the same time interval, while the differences in DeltaU/DeltaB according to (4) and (5) reach 0,11, apparently being a sequence of peculiarities of individual ubv systems. Therefore one cannot conclude that gradient differences of such an order indicate different optical radiation properties of variable stars. The slopes of V,B and U/B relations change near minima for some novae. The above relations have a discontinuity near maximum for SN in NGC 1073. Values of the both gradients before maximum differ from those after maximum. The gradient DeltaU/DeltaB is different before and after the moment of the abrupt change of the light curve slope for SN in NGC 7331 (Fig. 1) Therefore on the basis of Table 1 there are reasons to conclude that the optical radiation properties before maximum differ from those after maximum for novae and supernovae stars. For novae the differences manifest mainly in U and for supernovae beside that in B and possibly in V regions. The optical radiation properties before maximum may be similar for novae and supernovae. After the maximum DeltaV/DeltaB and DeltaU/DeltaB both are close for different novae, while for supernovae DeltaV/DeltaB are close and DeltaU/DeltaB can be essentialy different. From the linear regressive dependences for V,B and U,B it follows that the relations between changes in UBV pe magnitudes are of a statistical nature and DeltaV, DeltaB and DeltaU are proportional one to another in the same sence. Table 1 Before maximum After maximum Literat. DeltaV/DeltaB DeltaU/DeltaB DeltaV/DeltaB DeltaU/DeltaB source N Her 1960 1,09 0,96 1 N Her 1960 1,10 1,05 2 N Her 1963 1,20 1,06 3 N Her 1963 1,14 1,03 4 N Her 1963 1,16 1,14 5 N Del 1967 1,00 0,69 6 N Del 1967 1,07 0,88 7 N Del 1967 1,10 8 N Del 1967 1,05 0,98 9 N Vul 1968 1,00 1,03 10 N Vul 1968 0,98 1,05 9 SN in Virgo 0,58 1,00 11 SN in NGC 1073 1,00 0,77 0,66 1,06 12 SN in NGC 3389 0,59 1,38 13 SN in NGC 3389 B < 14,9m 0,54 1,35 14 SN in NGC 7331 V < 16,7m 0,64 2,00 15 SN in NGC 7331 V > 16,7m 0,64 1,00 15 mean 1,04 0,78 N 1,09 N 1,04 +/- 0,03 +/- 0,06 +/- 0,02 +/- 0,02 SN 0,61 SN 1,0-2,0 +/- 0,02 [FIGURE 1] Literature: [References] 1. L. Ross, PASP 72, 413, 1960 [BIBCODE 1960PASP...72..413R ] 2. P. F. Chugainov, Isv. Kr. AO 26, 217, 1961 3, M. Huruhata, Tokyo Astr. Bull. 11, N164, 1964 [BIBCODE 1964TokAB.164.2027H ] 4. K. Sdanavichus, R. Calitis Bull. Viln. Observ. 10, 137, 1964 5. G. Chincarini, PASP 76, 289, 1964 [BIBCODE 1964PASP...76..289C ] 6. D. I. K. O'Connell, Inform. Bull. Com. 27 IAU 313, 1968 [IBVS 313] 7. B. Onderlicka, M. Vetesnik, BAC 19, 99, 1968 [BIBCODE 1968BAICz..19...99O ] 8. I. Grygar, L. Kohoutek, P. Harmanec, BAC 19, 101, 1968 [BIBCODE 1968BAICz..19..101G ] 9. O. P. Abuladse, AC 500, 1969 10. O. P. Abuladse, Inform. Bull. Com. 27 IAU 324, 1969 [IBVS 324] 11. M. Mihalas, PASP 74, 116, 1962 [BIBCODE 1962PASP...74..116M ] 12. F. Bertola, A Ap 27, 319, 1964 [BIBCODE 1964AnAp...27..319B ] 13. O. Gingerich, Circ. Centr. Bur. for Tel. IAU N2004, 1967 14. G. de Vaucouleurs, J. E. Solheim, R. Brown, Astrophysica 3, 565, 1967 15. H. Arp, Ap J 133, 833, 1961. [BIBCODE 1961ApJ...133..883A ] F. I. LUKAZKAYA Main Astronomical Observatory of the Ukrainian Academy of Sciences