Bruce MacDonald wrote: > Thanks to everyone who replied to my message about elsets for > Sputnik 1 and the R-7 rocket. > > I have another question. When working out the brightness of > the payload and rocket I calculated that the payload would be > around mag 6 and the rocket mag 0 (based on 50% phase at > 500km range). I would be interested to learn from anyone who > may have seen them what the brightness of each object actually was. The observation reports of the rocket published by the SAO ("SAO Special Report 10 - Processed Observational Data for U.S.S.R. Satellites 1957 Alpha and 1957 Beta", Mar 1958) ranged in brightness between mag 0 and 4, typically mag 1 or 2. The satellite ranged between mag 4 and 7, typically mag 5 or 6. When I complete my orbital analysis of this data, I will determine standard magnitudes. For now, I suggest std mag 1.7 for the rocket, and 9.6 for the payload, both 1000 km, 90 deg phase angle. I have verified the value for the rocket against a small number of observations; the value for the payload is based upon its diameter, 0.58 m, and a brightness chart in Observing Earth Satellites, by Desmond King-Hele. It yields mag 6 predictions for favourable passes near perigee. Ted Molczan ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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