The opposition of Jupiter, 1953–’54

2024 February 8

Richard McKim

No BAA report for Jupiter in 1953–’54 has previously appeared. The apparition of 1952–’53 had been one of great activity, with a vigorous Revival of the South Equatorial Belt (SEB). During 1953–’54, in contrast, Jupiter was quiescent. The Red Spot Hollow (RSH), which had formed in the wake of the SEB Revival, was ever present and changeable, though its contrast with the South Tropical Zone had been greatly reduced by the presence of widespread shading across the latter. The Great Red Spot became faintly visible late in the apparition. The SEB had expanded to the south, but the S. component had faded considerably since the Revival. There was a small dark spot at the N. edge of the SEB(S) preceding the RSH, like two others seen during 1950. The S. edge of the North Equatorial Belt (NEB) had become unusually quiet, with fewer festoons. The latter showed marked positive movements in System I, yielding an exceptionally slow mean drift for the North Equatorial Current: at the time, the slowest on record. The NEB had widened, its N. edge extending to zenographic latitude +21°. The North Temperate Belt was displaced northward and appeared fragmentary, owing to the presence of darker spots and sections upon its N. component and the North Temperate Zone Band (NTZB). One lengthening and fragmenting section of NTZB had persisted since 1952–’53. We present accurate belt latitudes, not previously available for most of the 1950s oppositions, and synthetic colour images made from professional photographs for both the 1952–’53 and 1953–’54 apparitions.

Introduction

Opposition occurred on 1953 Dec 13 at declination +23°. Much useful work was accomplished by the BAA Jupiter Section under the directorship of Dr A. F. O’D. Alexander, with the assistance of W. E. Fox, but apart from a brief note and published average drift rates for three currents,^1,2 no descriptive account was ever written.

During 1949, there had been a Revival of the South Equatorial Belt. The Great Red Spot (GRS) subsequently faded, with the Hollow (RSH) visible throughout 1950. The GRS weakly reappeared in 1951–’52, intensifying by the following apparition. Another SEB Revival occurred during 1952–’53, leading to a further fade of the GRS, so that the RSH aspect again prevailed during 1953–’54. The 1949 Revival had been strongest in its Central Branch, but the 1952–’53 event had been stronger in the N. Branch, a difference that led to a dramatic slowing of the N. Equatorial Current. Significant latitude changes in the equatorial belts also occurred. The post-Revival South Tropical Zone had become dull in 1950, and the same phenomenon was even more marked in 1953–’54.

Useful series of Central Meridian (CM) transit timings in the UK were contributed by W. E. Fox, B. Burrell, A. P. Lenham and B. M. Peek. The longest series was made by E. J. Reese (Uniontown, Pennsylvania, USA) using his 152mm reflector, but this time he obtained only 347 timings, and the overall total was lower than usual, mostly owing to unfavourable UK weather in 1954 January–February. In contrast to the previous year, G. E. D. Alcock, F. M. Bateson and W. H. Haas had been unable to observe: they usually contributed many transits. It was therefore advisable to make an extensive series of measurements upon the available photographs and the best drawings in order to have a good number of longitude measurements available.

Other observers (based in the UK except where stated) were D. P. Avigliano (Sierra Madre, CA, USA), R. A. Blackett, E. H. Collinson, S. Cortesi (Geneva, Switzerland), E. L. Ellis, E. Epstein (Hollywood, CA, USA), J. Friends, J. A. Gould, E. R. Higgs, M. B. B. Heath, D. L. Livesey (Oundle School), F. T. Maloney, N. G. Matthew, P. A. Moore, O. C. Ranck (Milton, Pennsylvania, USA), J. Hedley Robinson, the Royal College of Science, London (via M. Gadsden); G. Ruggieri (Mestre, Italy), G. E. Satterthwaite, J. Russell Smith (Eagle Pass, Texas, USA), G. E. Taylor, F. H. Thornton (who made coloured sketches with his 457mm reflector), E. A. Whitaker (Royal Greenwich Observatory (RGO)) and A. P. Williams. Ruggieri had access to the 370mm refractor of Arcetri Observatory. Useful photographs were secured by L. T. Johnson (La Plata, Maryland, USA) with his 254mm reflector.

In addition to analysing the BAA data, the writer of this paper made use of observations by W. Löbering in Germany (kindly provided by H-J. Mettig) as well as a good set of photographs taken at Pic du Midi Observatory.³ The less numerous photographic plates taken by E. C. Slipher were scanned from the Lowell Observatory archive by Lauren Amundsen, and the writer together with Johan Warell made stacked composites, from which Manos Kardasis skilfully generated a single colour image. Kardasis and John Rogers made an excellent colour composite image for 1952–’53 for comparison, using images from the Hale Observatories. The best photographs were measured for latitude. Contemporary but very incomplete reports were published by the ALPO (based upon very few transits), ⁴ S. Cortesi,⁵ and G. Ruggieri.⁶ Gianluigi Adamoli skilfully translated parts of Ruggieri’s paper.

The BBC televised Jupiter through the 36-inch Yapp reflector at the RGO on 1954 Jan 13. E. A. Whitaker, then an Assistant to the Section Director, was involved with the broadcast.⁷

The observations extended from 1953 July to 1954 May. Limiting solar conjunctions occurred on 1953 May 25 and 1954 Jun 30. The present paper is a continuation of the comprehensive 1952–’53 BAA report,⁸ and in conjunction with our recent publications,⁹ restores further continuity to this decade. We intend to cover the following two apparitions, of which only the highlights were reported at the time.¹⁰

The observations

Figure 1 compares the 1952–’53 and 1953–’54 apparitions, showing the longitude of the GRS before, during and after a SEB Revival.

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