LIII Congress of the Società Astronomica Italiana (S.A.It.), L'Universo quattro secoli dopo Galileo,
Pisa 4-8 May, 2009
Talk: GRB
080319b and SN1054 Abstract: A typical SN Type
IIp model can fit the SN1054 explosion light curve when data coming
from European sources are also considered. Though a detailed
study of these texts reveals a number of problems in their precise
datation, it is likely that they actually describe the observation
of an unusual celestial event which occurred in a day near to the
one of the Pope Leo IX death (April 19th, 1054). In particular, they
seem to show that a very bright transient celestial phenomenon,
lasting about 30 min, was observed. We already suggested that this
Medieval testimonies were due to a very short and bright light flash
in the first phase of the SN precursor collapse. The discovery
of a similar flash in GRB 080319b brought us to consider this
hypothesis more deeply. We thus scaled the intensity of the GRB
080319b to the typical energy of a Type IIp SN and to a distance of
1.83 kpc, in order to evaluate the intensity of a similar flash in
the SN1054. We then took this value as input of the atmospheric
optical effects simulation code “HaloSim3”, using the point-like
source option for the dates and sites reported in European texts
connected with the SN1054 event, and in various atmospheric
conditions. The results are remarkably similar to the effects
reported in Medieval chronicles.
VII Annual Symposium of the
Italian Society for Archeoastronomy (S.I.A.) Mensura Coeli, Ferrara (Italy),
17-18 October, 2008
Poster: Chi l'ha vista? CasA, un resto di supernova
inspiegato Abstract: Il resto di
supernova (SN) denominato CasA mostra chiaramente di esser stato
generato in una esplosione avvenuta in epoca recente. Studi di
carattere dinamico fanno supporre che l'età del resto possa essere
di soli 300 anni circa: l'esplosione dovrebbe quindi essere avvenuta
nel corso del XVII secolo, periodo storico che vide una intensa
attività ad opera di numerosi astronomi europei, mentre ancora
nell'Impero Cinese operavano gli specialisti dell'Ufficio
astronomico imperiale. Tuttavia, a parte l’indiretta e controversa,
possibile segnalazione nel catalogo di Flamsteed, nessuna nuova
stella fu più registrata dopo quella vista nel 1602 tra gli altri da
Keplero il cui resto, ben noto, si trova in tutt'altra zona del
cielo. Sono stati elaborati numerosi modelli che cercano di spiegare
la mancata osservazione dell'esplosione di CasA; nessuno di questi è
però completamente soddisfacente. In questo lavoro intendiamo
presentare un'ipotesi differente. Un passaggio della storia
dinastica cinese Chin Shu
riporta la apparizione di una stella ospite in una posizione
compatibile con quella di CasA nel 369 dC. Questa testimonianza non
è stata fino ad ora presa in considerazione a causa della mancanza
di conferme da altre fonti. Tuttavia una nostra analisi di opere di
arte paleocristiana risalenti allo stesso periodo mostra l'esistenza
di un appariscente fenomeno celeste anche nel cielo di Roma,
confermando così la realtà della testimonianza cinese. Se questa
diversa identificazione fosse corretta, l'esplosione del progenitore
di CasA sarebbe avvenuta circa 1300 anni prima della data fino ad
ora stimata; meccanismi di carattere fisico avrebbero poi accelerato
l'espansione del resto di SN. Diversamente, ciò che resta
dell’evento del 369 dC attende ancora di essere scoperto.
Contributo agli Atti del Convegno: Martocchia, A., Polcaro, V.F. (2009):Chi l'ha vista? CasA, un resto di
supernova inspiegato, submitted
Fifth Italian Meeting on
Compact Objects Astrophysics (CNOC V), San Vito Lo Capo (Italy),
11-14 September, 2007
Talk: SN 185 and its Proposed Remnants Abstract: After
Clark and Stephenson (1977), on the basis of some positional
information given by the ancient text Houhan-shu, proposed to identify the SN remnant
G315.4-2.3 (RCW 86) with the historical SN seen by Chinese observers
in the year 185 of the modern era, a lot of work has been done by
theoreticians and observers to test the hypothesis.
This identification is challenged, in particular, by the absence of
any observed plerion in RCW 86. Several authors proposed the SNR
G320.4-1.2 (RCW 89) as a better candidate, while, on the basis of a
reinterpretation of the Houhan-shu,
even the very nature of the AD 185 event was questioned, leading to
the hypothesis that Chinese observers had actually witnessed a comet
transit (Chin & Huang, 1994) or a combination of the transit of
comet P/Swift-Tuttle with a Nova apparition (Schaefer; 1995, 1996).
Evidences supporting these different hypothesis will be presented.
(with V.F. Polcaro)
SEAC 2007 Conference, Astronomy and Cosmology in Folk
Traditions and Cultural Heritage, Klaipeda (Lithuania), 22
-31 July, 2007
Talk: Were the 185 a.d. and 369 a.d. “guest stars”
seen in Rome? Abstract: Since Clark and
Stephenson (1977) proposed that the supernova remnant (SNR)
G315.4-2.3 should be identified with the historical supernova (SN)
seen by Chinese observers in the year A.D. 185, a great deal of work
has been done by theoreticians and observers to test the hypothesis.
Some authors have proposed the SNR G320.4-1.2 as a better candidate,
while, on the basis of a reinterpretation of the Houhan-shu original
text, even the very nature of the A.D. 185 event has been
questioned, leading to the hypotheses of a cometary transit (Chin
and Huang 1994) or a combination of Comet P/Swift-Tuttle and a nova
(Schaefer 1995, 1996). In fact, a cometary transit was apparently
registered in one of the Priscilla Catacomb frescoes, an ancient
Roman artwork dating from the end of the second century. During our
examinations of Roman Catacomb frescoes in an attempt to discover
representations of "guest star" apparitions in Imperial Rome, we
also discovered what seems to be a record of SN 369, indicating that
this may have been the explosion which originated Cas A. Proceedings contribution: Polcaro, V.F.,
Martocchia, A. (2008): Were
the 185 a.d. and 369 a.d. “guest stars” seen in Rome? [IV.
ASTRONOMICAL AND COSMOLOGICAL KNOWLEDGE IN HISTORICAL SOURCES
AND LITERATURE.], Archaeologia Baltica, Institute of Baltic Sea region history
and archaeology, Klaipėda University Press, 10, 94-98
Talk: 11th
Century Supernovae: another way to read the Medieval sources? Abstract:
The supernova explosions of 1006 AD and 1054 AD are, probably, the
astronomical events most deeply studied by means of an analysis of
historical sources. But contradictions are still present in several
sources concerning SN 1054 and ther is not consistency between
historical records and astronomical data. This short analysis has
the aim to underline all these aspects. Proceedings contribution: Ghignoli, A.,
Martocchia, A., Polcaro, V.F. (2008): Eleventh Century Supernovae: another
way to read the Medieval sources?, Archaeologia Baltica, Institute of Baltic Sea region
history and archaeology, Klaipėda University Press, 10, 110-113
XXVI Congresso Nazionale di
Storia della Fisica e dell'Astronomia (SISFA 2006), Roma,
15-17 Giugno 2006
Abstract
del
Talk: Astrofisica delle Supernovae a partire
da documenti medioevali
Contributo agli Atti del Convegno: Polcaro, V.F., Martocchia, A.
(2007): Le Supernovae
nei documenti medioevali, in stampa