Flamsteed Astronomy Society

Rosemary Selmes — April 9, 2005

Memoirs of a young astronomer in Herstmonceux

Rosemary Selmes entertained us with enthusiasm and humour as she shared her reminiscences of life at Herstmonceux in the late-60s.  She joined the Royal Greenwich Observatory as a Scientific Assistant in 1967.  A career in astronomy was less a calling to follow in the footsteps of Tycho, and more a consequence of having done the wrong GCEs to pursue pathology!  She joined just as astronomers were scratching their heads about strange newly-discovered star-like objects showing huge red-shifts and amazing variations in brightness.  Dubbed ‘quasars’ (quasi-stellar radio sources) by Maarten Schmidt, they were then the subject of intense investigation and Rosemary was just in time to be assigned assistant to two new high-flyers down from Cambridge.   Rosemary worked 7 years at the RGO, mostly using the 26-inch Thompson refractor which had started life at Greenwich.  When not working on the 26-inch, she had use of an office in the castle overlooking the moat.   She remembers how in Spring, staff would rescue the ducklings and move them to the castle courtyard, safe from the depredations of the carp in the moat.  Rosemary’s office had last been used by the Astronomer Royal, Sir Richard Woolley.  He had moved elsewhere in the castle, possibly to be able to reach the croquet lawn more quickly.

The 26-inch was a gift to the ROG in 1896 by Sir Henry Thompson, local surgeon and amateur astronomer.  Built by Howard Grubb in Dublin, it was mounted in the South Building dome at Greenwich until 1947.  It was moved to Herstmonceux in 1957-8 where it remains today.  Rosemary and her husband Lester, were closely involved in restoring the telescope in the late-1990s.  The 26-inch has fitted as finder the 12.8-inch Merz, Airy’s original ‘Great Equatorial’.  Bought in 1859 following  the ‘Neptune scandal’, the Merz cost £1144 2s 6d, and was mounted in the Great Equatorial dome at Greenwich, now home to the 28-inch.  The Thompson 26-inch is a photo-refractor, essentially a large camera optimised for the photographic emulsions of the late-1890s.  Each dome at Herstmonceux had a moveable darkroom, a 4 ft x 4 ft cupboard on castors where photographic plates could be prepared.  The darkroom had to be mobile so it could be moved out of the way of the telescope travel.  Rosemary’s duties included many a long night of observing with the 26-inch.  She described the nightly set-up procedure for the 26-inch which makes set-up on the Greenwich 28-inch now seem like a piece of cake.  Complications included positioning of the lifting floor in the dome and manual setting of precise sidereal time on the RA ring (10 secs. ahead to allow you time to get round and engage the RA drive!).  Manual setting of RA and Dec. coordinates was necessary, both through magnifying tubes with little illumination in an otherwise pitch-black dome, and using fingers often frozen stiff in the cold!  Photographs of the quasars could only be achieved during the dark of the Moon and required exposures around an hour long.  The RA drive couldn’t be relied on for this long and the scope had to be manually monitored and continuously adjusted to make sure it was a good exposure.

Thompson 26-in photo-refractor at Herstmonceux.  Merz 12.8-in fitted as finder

Working alone in the dome, there were few comforts available.  No kettles, no personal stereos.  Only a radio playing Radio Luxembourg (“...that’s Keynsham, spelled K-E-Y-N...”) might keep you alert.  An unwary observer could be rewarded for falling asleep on the chair by finding themselves pinned-down by the telescope as it moved relentlessly in RA!  Lady Woolley expressed concern about the well-being and moral protection of the young ‘gels’ working alone all night but there was little done to help.  It was sometimes necessary to lock yourself in the darkroom to avoid the unwanted assistance of an equally lonely night-watchman.   Outside the domes there were just as many pit-falls (literally) for the unwary.  The ‘modern’ design of the Herstmonceux Equatorial Group created an obstacle course of sheer drops and a pond, all of which had to be avoided in the pitch-black with only a tiny hand torch and often with hands full of papers and equipment.  The lifting floor of the 26-inch dome was an extra hazard. 

Refractor domes at Herstmonceux.  The 26-inch is in the far dome

When raised it meant the dome door was another 4 feet above the ground, another trap waiting to catch the forgetful. Only minimal time-off was given for night-duty and Rosemary was also responsible for analysing the brightness of the target quasars using an iris photometer.  The size of the quasar image on the plate was compared with nearby stars of known magnitude.  Quasars are now thought to be the core of very active galaxies possibly powered by massive black holes.  Rosemary’s work contributed to understanding the behaviour of these objects including BL Lacertae (first discovered quasar, and given a variable-star name) and 3C-371.

Rosemary with the 28-inch at Greenwich

After 7 years Rosemary left the RGO and now has a career in rehabilitative exercise, but her interest in Herstmonceux and astronomy has re-kindled.  She concluded the talk with a series of photographs from the construction of the Herstmonceux site.  Rosemary reflected that at the RGO her knowledge of astronomy was almost exclusively confined to quasars, but her time there planted a love and fascination with the night sky that she can now pursue much more broadly.