987 Wallia (provisional designation: or ) is a large background asteroid from the outer regions of the asteroid belt, approximately in diameter. It was discovered on 23 October 1922, by astronomer Karl Reinmuth at the Heidelberg Observatory in southern Germany. The D/T-type asteroid has a rotation period of 10.1 hours and shows an unusual trinomial lightcurve. It was named after a common German female name, unrelated to the discoverer's contemporaries, and taken from the almanac Lahrer Hinkender Bote. Orbit and classification Wallia is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements. It orbits the Sun in the outer asteroid belt at a distance of 2.4–3.9 AU once every 5 years and 7 months (2,031 days; semi-major axis of 3.14 AU). Its orbit has an eccentricity of 0.24 and an inclination of 9° with respect to the ecliptic. On 8 August 1899, Wallia was first observed as A899 PJ () at the Boyden Station of the Harvard Observatory in Arequipa, Peru (the observatory has since moved to South Africa). The body's observation arc begins at the Vienna Observatory on 22 December 1922, about two months after to its official discovery observation at Heidelberg. Naming This minor planet was named "Wallia", after a female name picked from the Lahrer Hinkender Bote, published in Lahr, southern Germany. A Hinkender Bote (lit. "limping messenger") was a very popular almanac, especially in the alemannic-speaking region from the late 17th throughout the early 20th century. The calendar section contains feast days, the dates of important fairs and astronomical ephemerides. For 13 October, the calendar gives "Wallia" as the German analogue for Koloman (Saint Colman) and Eduard, the respective catholic and protestant feast-days. Latter is likely related to Saint Edward the Confessor (1004–1066), whose feast day is also 13 October. Reinmuth's calendar names As with 913 Otila, 994 Otthild, 997 Priska and 1144 Oda, Reinmuth selected names from this calendar due to his many asteroid discoveries that he had trouble thinking of proper names. These names are not related to the discoverer's contemporaries. The author of the Dictionary of Minor Planet Names learned about Reinmuth's source of inspiration from private communications with Dutch astronomer Ingrid van Houten-Groeneveld, who worked as a young astronomer at Heidelberg. Physical characteristics In the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), Wallia is a