Supernova SN 1006 in two historic Yemeni reports

Abstract

We present two Arabic texts of historic observations of supernova SN 1006 from Yemen as reported by al-Yamani and Ibn al-Dayba (14th to 16th century AD). An English translation of the report by the latter was given before (Stephenson & Green 2002), but the original Arabic text was not yet published. In addition, we present for the first time the earlier report, also from Yemen, namely by al-Yamani in its original Arabic and with our English translation. It is quite obvious that the report by Ibn al-Dayba is based on the report by al-Yamani (or a common source), but the earlier report by al-Yamani is more detailed and in better (Arabic) language. We discuss in detail the dating of these observations. The most striking difference to other reports about SN 1006 is the apparent early discovery in Yemen in the evening of 15th of Rajab of the year 396h (i.e. AD 1006 Apr 17 \pm 2 on the Julian calendar), as reported by both al-Yamani and Ibn al-Dayba. i.e. about 1.5 weeks earlier than the otherwise earliest known reports. We also briefly discuss other information from the Yemeni reports on brightness, light curve, duration of visibility, location, stationarity, and color.Comment: 9 pages with 3 figure

Interpretation of the historic Yemeni reports of supernova SN 1006: Early discovery in mid‐April 1006?

“…Muslim dates run from one evening to the next evening, and a month starts with the evening of the first sighting of the crescent of a new moon. It was confirmed in Rada and Neuhäuser () that the conversion of 1 Sha c bān 396h to AD 1006 May 2/3 is correct when considering the first observation of the crescent (and also regarding the given weekday). In general, unless more information is available, the conversion from the calculated Islamic calendar to the Julian or Gregorian calender has an uncertainty of some 2 days due to (a) uncertainty in the start of the Hijra era (1 day), (b) uncertainty as to which months and years in history had one extra day (in addition to 354 days in 12 lunar months—given that a synodic month is not exactly 29.5 days), and (c) uncertainty as to when the new crescent moon was sighted first (e.g., Neuhäuser & Kunitzsch, ; Spuler, ; Spuler & Mayr, ).…”

“…Most recently, Rada and Neuhäuser () presented two more Arabic reports on SN 1006 in both Arabic and English translation, by the Yemeni historians al‐Yamānī and Ibn al‐Dayba c . An English translation of the latter text was first presented in SG02 quoting private communication with one of us (W.R.).…”

“…An English translation of the latter text was first presented in SG02 quoting private communication with one of us (W.R.). In Rada and Neuhäuser (), the dating of the observations is discussed in detail.…”

“…SN 1006 is believed to have taken place on AD 1006 April 30 or earlier (see Rada & Neuhäuser, ) in the constellation of Lupus with the following basic parameters: The distance is 2.18 ± 0.08 kpc from the proper motion of ejecta in mas/year and the shock velocity of filaments in km/s (Winkler, Gupta, & Long, ); The extinction is A V = 0.32 ± 0.03 mag (Schaefer, from various techniques) or A V = 0.31 ± 0.10 mag (Winkler et al, ) from the reddening of the very blue sub‐dwarf (Schweizer & Middleditch, ) showing strong, broad absorption lines due to the SNR, so that it is located in the background at 1.05–2.1 kpc (Burleigh, Heber, O'Donoghue, & Barstow, ) to 1.5–3.3 kpc (Schweizer & Middleditch, ). The peak apparent brightness is −7.5 ± 0.4 mag from distance for an SN type Ia (Winkler et al, ). The apparently young SNR G327.6+14.6 was identified as its remnant (Gardner & Milne, ; Reynolds, Lyutikov, Blandford, & Seward, ). …”

“A red cross appeared in the sky” and other celestial signs: Presumable European aurorae in the mid AD 770s were halo displays

“…It showed a great turbulence (al-Yamānī from Yemen, Rada & Neuhäuser 2015), it was not round, but rather was elongated; at its edges were [lines like] fingers. It showed a great turbulence (Ibn al-Dayba c from Yemen, Rada & Neuhäuser 2015). These apparent elongations are due to very strong scintillation of a very bright object (−7.5 mag).…”