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

Abstract

The recently published Yemeni observation report about SN 1006 from al‐Yamānī clearly gives AD 1006 April 17 ± 2 (mid‐Rajab 396h) as the first observation date. Since this is ∼1.5 weeks earlier than the otherwise earliest reports (April 28 or 30) as discussed so far, we were motivated to investigate an early sighting in more depth. We searched for additional evidences from other areas like East Asia and Europe. We found that the date given by al‐Yamānī is fully consistent with other evidence, including the following: (a) SN 1006 rose several times half an hour after sunset (al‐Yamānī), which is correct for the location of Ṣancā' in Yemen for the time around April 17, but it would not be correct for late April or early May. (b) The date (third year, third lunar month, 28th day wuzi, Ichidai Yoki) for an observation of a guest star in Japan is inconsistent (there is no day wuzi in that lunar month), but may be dated to April 16 by reading a wuwu date rather than a wuzi date. (c) There is observational evidence that SN 1006 was observed in East Asia in early or mid‐April; for the second half of April, a bad weather (early monsoon) period is not unlikely— there is a lack of night reports. (d) The observer in St. Gallen reported to have seen SN 1006 for 3 months, which must have ended at the very latest on AD 1006 July 10, given his northern location, so that his observations probably started in April. We conclude that the correctly reported details give quite high confidence in the fully self‐consistent report of al‐Yamānī, so that the early discovery date should be considered seriously.

New sunspots and aurorae in the historical Chinese text corpus? Comments on uncritical digital search applications

“…We will now consider four more presumable aurorae listed in table 2 of H+15 (Chinese text in our Figure ), somewhat related to each other, which were previously discussed in Neuhäuser et al (): there are two entries for AD 1006 Apr 14 (brackets are our additions, but as meant in H+15): 1006 Apr 14 R[ed] V[apour] n[orth] [in] Kaifeng [lunar phase] 0.46 and 1006 Apr 14 W[hite] V[apour] near the moon [in] Kaifeng [lunar phase] 0.46 (0.46 means near full moon). One of the two texts is from the astronomical treatise ( Tianwen zhi ) of the Song Shi , and the other from its treatise on general omenology ( wuxing zhi ).…”

“…There is another instance of the same phrase ( yellow vapor like a pillar penetrated the moon ) dated to the fourth month of the third year of the Tianxi reign period (AD 1019) given without the guimao date—even though there is a guimao date in that month (AD 1019 Mar 23, close to full moon on May 21/22). It is possible that the event somehow got transposed to the wrong reign period (Neuhäuser et al ).…”

“…They omitted the wording penetrated the moon , which is clearly given in the original Chinese (see our Figure ); H+15 give 0.04 as lunar phase (new moon May 7), so that again the text (penetrated the moon) is not consistent with the lunar phase for the date given in H+15. This event was most probably a lunar halo pillar rather than an aurora (Neuhäuser et al ).…”

Critical comments on publications by S. Hoffmann and N. Vogt on historical novae/supernovae and their candidates

“…Connections of historical transients with SNe or novae are problematic in particular due to difficulties in the understanding of historical texts, which could be improved by transdisciplinary collaboration between astrophysicists, philologists, and historians—such a project is undertaken by us since 2012 under the name of Terra‐Astronomy (see Neuhäuser et al 2020). We have already studied various phenomena, for example, historical SNe (new Arabic records of SN 1006 in Rada & Neuhäuser 2015 and Neuhäuser et al 2017a, 2017b as well as of SNe 1572 and 1604 in R. Neuhäuser et al 2016b), comets in the late 8th century (e.g. Chapman et al 2014, 2015), and reconstruction of solar activity around AD 775 from aurorae and radiocarbon (e.g.…”

Novae, supernovae, or something else? -- (Super-)nova highlights from Hoffmann & Vogt are quite certainly comets (AD 668 and 891)

“…A recent review on historical SNe is found in Stephenson & Green (2002); a few additional Arabic language records of SNe 1006, 1572, and 1604 are collected in Rada & R. , R. Neuhäuser et al (2016Neuhäuser et al ( , 2017a, and R. Neuhäuser, Ehrig-Eggert & Kunitzsch (2017b). Recent work on historical 'guest stars' including novae and SNe can be found in Stephenson & Green (2005, 2009, a cometography in Kronk (1999), a critical collection of Chinese records of 'broom ' and 'fuzzy stars' in Pankenier, Xu & Jiang (2008, henceforth P+08) -all ignored in HVP20 and HV20a,b.…”