and Stephenson investigated other entries in Song Shi, which also includes reference to "standing on guard". They selected entries relating to conjunctions betweens the stars identified and planets, of which the trajectory can be calculated without difficulty and with great precision on the indicated dates. Of the 18 conjunctions analysed, spreading from 1172 (the Jupiter–Regulus conjunction on 5 December) to 1245 (the Saturn–Gamma Virginis conjunction on 17 May), the planet was more to the north (in the sense of a lower declination) in 15 cases, and in the three remaining cases, it was never in the south quadrant of the star. In addition, Stephenson and Clark (1977) had already highlighted such an inversion of direction in a planetary conjunction: on 13 September 1253, an entry in the astronomical report Koryo-sa indicated that Mars had hidden the star to the south-east of the twenty-eight mansions sign Ghost (Delta Cancri), while in reality, it approached the star north-west of the asterism (Eta Cancri). Meigetsuki (Japan) The oldest and most detailed record from Japan is in the Meigetsuki, the diary of Fujiwara no Teika (1162–1241), a poet and courtier. There are two other Japanese documents, presumably dependent on the Meigetsuki: The 14th century Ichidai Yoki: The description is very similar to the Meigetsuki, omitting several details (hour of apparition, and possibly erroneous parts of the lunar month). The short text also contains many typographical errors. The 17th-century Dainihonshi, containing very little information. The brevity contrasts with the more detailed descriptions of "guest stars" (supernovas) of 1006 and 1181. The Meigetsuki places the event in the fourth lunar moon, one month earlier than the Chinese texts. Whatever the exact date during this month, there seems to be a contradiction between this period and the observation of the guest star: the star was close to the sun, making daytime and nighttime observation impossible. The visibility in daylight as described by the Chinese texts is thus validated by the Japanese documents, and is consistent with a period of moderate visibility, which implies that the star's period of diurnal visibility was very short. In contrast, the day of the cycle given in the Chinese documents is compatible with the months that they state, reinforcing the idea that the month on the Japanese document is incorrect. The study of other medieval supernovas (SN 1006 and SN 1181) reveals a proximity in the dates of discovery of a guest