Papers – Page 23 – British Astronomical Association

Spectral changes in AC Herculis during its rise to a maximum in 2014 July

Four low resolution (R~1000) spectra were obtained of the RV Tauri-type variable AC Her during its rise from a deep minimum in July 2014. These show changes in spectral type and Balmer line equivalent width as the star brightened, consistent with earlier observations.

The controversial pen of Edwin Holmes

Edwin Alfred Holmes (1839-1919) is best remembered for his discovery of a bright comet in 1892, now known as Comet 17P/Holmes. An amateur astronomer and authority on optics, he was an original member of the BAA and contributed to its Journal and meetings for many years. As a prolific writer of letters to English Mechanic, he developed a reputation for his controversial and acerbic penmanship.

HW Boötis: an enigmatic cataclysmic variable star

We present the 13-year lightcurve of HW Boo between 2001 May and 2014 May. We identified 12 outbursts, which typically lasted 2 to 5 days, with an amplitude of 2.7 to 3.6 magnitudes. We discuss whether HW Boo might be a dwarf nova of the SU UMa family or an Intermediate Polar, but further observations are needed to support classification.

The brighter comets of 2005

This report describes and analyses observations of the brighter or more interesting comets discovered or at perihelion during 2005.

William Sadler Franks and the Brockhurst Observatory

William Sadler Franks (1851-1935) was astronomer-in-charge at F. J. Hanbury’s private observatory at Brockhurst, near East Grinstead, Sussex, from 1909 until his death in 1935. This paper reviews the observational projects Franks undertook at Brockhurst, including his work on double stars, red stars, diffuse nebulae and dark nebulae, as well as his involvement with the commissioning of a 24-inch reflector built by Thomas William Bush.

Perseids 2013 – Multi-station meteor videography

The results from multi-station observations of the 2013 Perseids meteor shower are presented and discussed, including an estimate of the Perseids’ population index.

Saturn in 1995−’96

BAA observations between 1995 April and 1996 February are reviewed. Highlights of the apparition were observations of the phenomena of the triple ring-plane crossings by the Earth and the ring-plane crossing of the Sun, the results of which show that the predicted times were correct to within a few hours. Transits and shadow transits of Titan, Rhea, Dione and Tethys were observed. Several mutual satellite events were also observed, either visually or by means of CCD cameras. White spot activity could again be followed in the planet’s northern Equatorial Zone (EZ), though it was much reduced from 1994-’95: the long-enduring white spot (WS1) had survived solar conjunction and continued to move with a rotation period close to 10h 22m, as did another short-lived feature…

In the footsteps of Ebenezer Porter Mason and his nebulae

In 1839, Ebenezer Porter Mason (1819-1840) produced detailed drawings of the Omega Nebula (M17), the Trifid Nebula (M20) and the eastern part of the Veil Nebula. This paper reviews his life and his observations, comparing his results with those of the modern amateur astronomer.

Changes in the spectrum of Z Ursae Majoris during its rise through a maximum in 2014 June

The semiregular variable Z UMa experienced a particularly deep minimum at the end of 2014 March, followed by a three-month rise to maximum.

Early research on the effects of solar eclipses on radio propagation

Research prompted by a slide included in a recent presentation recalling some of the contents of the archives of the Radio Society of Great Britain. This mentioned the involvement of the radio astronomy community in a study of radio propagation conditions a few days either side of the 1927 total solar eclipse.