Six-Color Observations of RS Ophiuchi

Abstract

During the 1958 outburst of the recurrent nova RS Ophiuchi, sixcolor observations of this star were made by the writer with the Tauchmann 22-inch reflector of the Lick Observatory. An infraredsensitive Lallemand photomultiplier with a combination of filters was used. The photometer has been previously described (Kron 1958a). The observed colors were reduced to the standard six-color system by comparison with the six-color data for nonvariable stars given by Stebbins and Kron (1956).

CCD photometric search for peculiar stars in open clusters

“…Svolopoulos (1966) lists E(B − V ) = 0.08 mag whereas Kjeldsen & Frandsen (1991) give E(B − V ) = 0.70 mag as best value. This results in a difference of 560 pc versus 2100 pc and 5 Gyr versus 0.2 Gyr, respectively.…”

“…Col. 13: Deviation from cluster line a0 = a + b · (B − V ) using the corresponding constants as listed in Table 2. Piatti et al (1998; and other references which can be found therein) used the values of Svolopoulos (1966) Before we try to disentangle these discrepancies, an overview of the results from the ∆a-photometry is presented. Figure 2 shows a well defined main sequence with about 25 probable non-members.…”

“…The conclusions of Svolopoulos (1966) and Lyngå (1987) are based on estimates from photographic plates which do not take into account any effects by the crowding of the field and result normally in much larger errors than CCD photometry. Note that Kjeldsen & Frandsen (1991) reported problems in calibrating their U and B values to standard ones because the combination of the characteristics for the used filter and the CCD response function was far from the original ones.…”

Strömgren uvby photometry of the open clusters NGC 6192 and NGC 6451

“…For NGC 6451, Svolopoulos (1966) lists a reddening E(B − V) = 0.08 mag whereas Kjeldsen & Frandsen (1991) give E(B−V) = 0.70 mag as the best value resulting in a difference of 560 pc versus 2100 pc and 5 Gyr versus 0.2 Gyr, respectively. The situation for NGC 6192 is almost identical.…”

Détenteas a Strategy: Greece and the Communist World, 1974–9

“…The only negative reply came from Tirana. 42 The 1976 Balkan Conference was a strange affair. All sides were evidently interested in expanding their co-operation.…”