Astronomers used the 2.1-meter telescope of the McDonald Observatory in Texas to detect the latest six exocomet systems. Faint absorption lines, detected by the telescope, were found to vary from night to night and suggested that this was caused by "large clouds of gas emanating from comets as they drew close to their host stars and heated up". All the most recently detected exocomet systems - namely, "49 Ceti (HD 9672)", "5 Vulpeculae (HD 182919)", "2 Andromedae", "HD 21620", "HD 42111" and "HD 110411" - are around very young type-A stars.
Exocomets are an important link in the understanding of planet formation according to researchers. Astronomer Barry Welsh describes the link as follows: “interstellar dust under the influence of gravity becomes blobs, and the blobs grow into rocks, the rocks coalesce and become bigger things – planetesimals and comets – and finally, you get planets.”