Variable star observations by Alexander William Roberts for the period 1891-1933

This series contains 95 sets of handwritten documents, dated between 1891 and 1933, containing original astronomical observations made by A. W. Roberts from his private observatory, Lovedale Observatory, near the town of Alice in the Eastern Cape Province, South Africa. In addition to the raw observations, there are also draft articles, long-hand calculations, diagrams, graphs, and custom star charts. Together, these documents allow a glimpse of how astronomical research was conducted in the late 19th to early 20th century. The material in this series describes 47 stars (R Ara, S Ara, R Cae, AF Car, l Car, R Car, S Car, X Car, Y Car, RR Car, R Cen, S Col, R CrA, R Cru, S Cru, R Dor, S Gru, R Hor, R Ind, S Ind, R Lup, S Lup, R Mus, S Mus, S Nor, R Oct, S Oct, R Pav, T Pav, S Pav, R Phe, S Phe, S Pic, L2 Pup, V Pup, W Pup, R Ret, R Scl, S Scl, T Scl, RZ Sco, RV Sgr, R Tel, R TrA, S TrA, T Tuc, and S Vel) of the 105 that Roberts observed. Most of the material is written on unbound pages, but sometimes scraps of paper and even official letterheads of the House of Assembly of the Parliament of the Union of South Africa was used. Roberts was interested in studying variable stars, a type of star that changes brightness over time, in the hope of understanding the mechanism for this change. When he began his self-taught work, only 35 variable stars in the southern hemisphere were known, and no star charts were available. Roberts would go on to discover several new variable stars, and for over 30 years he carefully monitored 105 variables, making over 70,000 observations. His observations are the earliest made in southern Africa, and significantly extend the time frame over which the behaviour of these stars is known. n/a. Extent: 95 enclosures containing 22,578 pages. Condition of original material: Generally in good condition. About 1% shows noticeable insect damage. Custodial history: Originally belonging to A. W. Roberts, the material was donated to Boyden Observatory after his death in 1938. Arrangement: Original arrangement by the creator. Author(s)/Creator(s): Alexander William Roberts (variable star observer and amateur astronomer). Scribe(s): N/a. Publisher(s): N/a. Editor(s): N/a. Volume number: N/a. Original institution reference: AWR.