As it was the first comet found in 1973, it received the provisional designation 1973a, in accordance with the system in operation at the time. Now that comets are being discovered in greater numbers the designation was changed to C/1973 A1 (first comet of the first half of the first month of 1973). It was also given the designation 1972 VIII in accordance with a system that has since been discontinued (the eight comet to pass the perihelion in 1972).

Without being spectacular, the Heck-Sause comet is quite an imposing object. Its size which was hastily announced to be 12 was seen to be closer to 9 or 10 when the remaining negatives were analysed. If we consider that the comet was far from the sun (r=2.72 astronomical units) and the Earth (Δ=2.25 AU) we can say that it was intrinsically brilliant. 

By taking account of the geometric effects alone, the magnitude of a comet must be corrected to 5(log(r) +log (Δ)). This relation expresses the idea that an object that is ten times further away from us appears to be a hundred times less bright and therefore loses 5 magnitudes. At the same time, if it is ten times farther than the sun it receives one hundred times less light and loses another five magnitudes. The application of this formula gives a magnitude of 5 for our comet at the distances r and Δ of 1 AU, ensuring that it is visible to the naked eye. As the activity of a comet increases considerably on approaching the sun, its brightness will be greater. To take account of this we empirically correct ®C and locally ®C, the above formula with an extra empirical term n*log(r), the factor n which can be as high as 10 or 20 which would signify an additional gain of 4 to 8 magnitudes.  It is therefore likely that, if it approached Earth’s orbit, the comet would have been spectacular.

The perihelic distance of the comet was more than 2.5 AU, and this point had already been passed at the moment of its discovery. Heck-Sause was moving away inexorably. Analyis of the orbit indicates a very long period. Undoubtedly the comet was making its first appearance in the vicinity of the sun having come from the Oort cloud, that vast reservoir of frozen heavenly bodies on the edge of the solar system.

Spectrums were rapidly taken at the observatory of Haute-Provence and they only showed the light reflected by the dust. The dilution of the solar radiation at these distances was not sufficient to set off the activity of the ®C gases, the factor n as mentioned above takes account as much as possible of this activation of gases near the sun. Not all comets behave like this. Astronomers had noticed the analogy with the comet C/1950 K1 (Minkowski) which, twenty years earlier, at an equivalent distance from the sun, showed practically no gas fluorescence in contrast with C/1961 R1 (Humason) which only showed a little dust and a lot of gas.

On the first negatives, the comet was seen to have a tail of half of one degree. The observations carried out over the following months revealed a tail extending for more than one and a half degrees in March 1973 (E.I. Shchukin at Irkoutsk with an astrograph of 50 cm). The comet was at its nearest to Earth on 11 February. It is a pity that it was not possible to use the deep negatives taken by the Franco-Liege Schmidt at this period. However, a hard copy of one of them (page 384), taken in the night of 29 to 30 January remains showing the considerable extension of the comet.

After the announcement of the discovery, the comet was found on negatives taken on the 4th of January by M. Koishikawa of the municipal observatory of Sendai, which shows the importance of a careful examination of images in order to avoid missing a discovery. Perhaps this observer had adopted the same strategy as André Heck, without carrying it through to the end.