THE DECANS AND THE ANCIENT EGYPTIAN
SKYLORE: AN ASTRONOMER’S APPROACH
JUAN ANTONIO BELMONTE
Instituto de Astrofisica de Canarias, 38200 La Laguna, Tenerife, Spain,
jba@ll.iac.es
ABSTRACT. In this work, a hypothetical identification of the ancient Egyptian decan stars or,
simply, decans is presented. This is based on an astronomical analysis of the original 36 decans of the
diagonal clocks located inside the coffin lids of the 1 st Intermediate Period (Dyn. IX to XI; c. 2100 BC).
Besides, we also present sensible translation for most of the terms according to their identification. The
results are compared with later representations of the decans in the New Kingdom and Greco-Roman
times. Previous proposals are also reviewed.
1. Introduction
To attempt to go further in the determination of the
decans is not only of very little interest but would
necessarily imply ascribing to our texts an
astronomical accuracy which they never intended to
have
O. Neugebauer (1957)
This extremely pessimistic sentence was written more than four decades ago by one
of the most important historians of astronomy so far (Neugebauer, 1969). Despite
his merits in the field (his “Egyptian astronomical texts”, edited with Richard Parker
in the 1960s, hereafter referenced as N&P, are a real masterpiece), statements like
this have severely handicapped any advance in ancient Egyptian skylore, specially
when focussed on an actual astronomical point of view. However, it is worth
mentioning that some effort have been devoted to other areas of ancient Egyptian
astronomy. General reviews can be found in Gallo (1998) and the excellent
compilation by Clagett (1995). Discussions on the calendar, after the classical work
of Parker (1950), can be found in Roy (1982), Wells (1994) and, most recently, in
the interesting work of von Bomhard (1999). Since the pioneering, and contested,
book of Lockyer (1894), Hawkins (1973, 1975), Krupp (1977, 1984, 1991), Haack
(1984), Leitz (1991), Belmonte (1999, 2000) or Spence (2000) have discussed on
archaeoastronomy and the problem of astronomical orientation.
Regarding the skies themselves (see Figure 1), after the early proposals of Petrie
(1940), where we already have the equations Sah (sAH) equal to Orion and Sepedet
(spdt) equal to Sirius, only in the last two decades some few attempts have been
made to identify ancient Egyptian constellations.
Figure. 1: The ancient Egyptian view of the skies at the beginning of the New Kingdom, represented on
the ceiling of the tomb of queen Hatshepsut’s favourite Senmwt. This is the earliest complete
representation of the Egyptian Heaven that we know (dated c. 1500 BC). The lower part represents the
northern sky constellations in the centre of the panel (we will deal with them in future works, see e.g.
Belmonte, 2001), surrounded by the 12 monthly festivals and 15 or 16 of the gods of the moon cycle. The
upper part includes the decans, starting by tpya knmt and finishing with Ast spdt (represented as
the goddess Isis-Sothis), 4 planets, with the Horus name of the queen, and the so-called triangular decans.
Notice also the southern constellations of Sah (represented by a man standing on a boat), the Circle (kd)
the Sheep (srt) and the Boat (wiA). Table 4 offers the complete list of the corresponding decans.
On the one hand, we have interesting approaches to the problem using the
mythological information contained in different sources, specially the Pyramid Texts
of the 5th and 6th Dynasties (Faulkner, 1969). The works of Davis (1985), Sellers
(1992) or Krauss (1997) are worth mentioning.
On the other hand, amongst the decan star (see Tables 1 to 5), N&P only
identified spd (or later spdt) with Sirius and located the decans of the Sah group
somewhere in the constellation of Orion, proposing that the rest of the decan stars
should be roughly located in the so-called “decanal belt”, located to the south of the
Ecliptic. One property of these stars (and asterisms), inferred from their
interpretation of the “Book of Nut”, was that they must have been suffered a period
of invisibility of 70 days between the dates of their heliacal setting and rising.
It is not until two decades later that we have the work of Böker (1984) who,
using a philological and mythological approach, do not consider the former ideas of
N&P and proposes a whole identification of the decans using stars and asterisms
scattered all around the sky. Some of his identifications are very interesting: xAw
with the Pleiades, art with Taurus or the Hyades, kdty with Corona Australis (but
also with Corona Borealis), xntt with Scorpio (including Antares like Tms n
xntt, the Red on the Front) or spd, which he translates as the Triangle, with
Sirius.
Others, however, are non-sense either from a philological or an astronomical
point of view. Examples are: hAt xAw with shooting stars, srt, translated as the
Highest and then identified with a star in the zenith, kd (translated as the Bed) with
Ursa Minor, which is a circumpolar star and can not be a decan star in any sense
since they were clearly chosen to mark the beginning of an Egyptian 10 day weeks
(decades) through their heliacal rising, etc.
Most interesting are the proposals of Locher (1981, 1985, 2001; reviewed by von
Bomhard, 2000) who, using N&P ideas and considering differences in ecliptic
longitude between different stars and asterisms, has produced quite sensible
identifications for some decans or, better, for their associated constellations (see
Figure 1): i.e. the Circle with the head of Cetus, the Sheep with our Capricornus or
the Boat (including xntt considered as its prow) like parts of Sagittarius and
Scorpio (with Antares as the Red of the Prow). However, the most important would
be the identification of the sAH [
] hieroglyphic with the asterism formed by
the Belt and the Sword of Orion (see Figure 2 and 3) and, consequently, ending the
equation Sah equal to (all) Orion. We will further mention these proposals in the
discussion.
Figure 2: Image of a part of the inner face of the coffin lid of Idy (c. 2150 BC, 1 st Intermediate Period).
There are four astronomical representations to the right: Nut, perhaps the Milky Way (Wells 1994),
mSxtyw (the Plough), sAH (part of Orion) and spd (part of Canis Major, including Sirius). The last two
have their hieroglyphic signs over their head. Part of the corresponding diagonal decan star clock is seen
to the left of the image, starting by Xry-ib wi3, the Heart of the Boat.
hghj
A
Fig. 3: Identification of the decan star in the area of sAH
and spd
, represented on the lower right
corner with their hieroglyphic crowns over their head. Following Locher (2001), the sAH sign would be
the belt and sword of Orion. We also propose that the crown of spd can be identified with 5 stars of CMa,
including Sirius (Sepedet). After that, the rest of the decans are easily identified. Specially suggestive
would be the identity of xAw, the Myriad or the Flock, with the Pleiades cluster (see Table 3). In later
sources, abwt was transformed into the decan sAH per excellence.
2. Discussion and conclusions
This was the situation when we decided to study the problem of the decans not from
later sources, but from the primary sources that we know, the diagonal clocks
painted in the interior of nearly a dozen of coffin lids of the 1 st Intermediate Period,
dated between 2150 and 2050 BC. N&P had studied in details those materials and
had proposed a comprehensive list of 36 original decans (with later variants, see
Table 3) that would have been used to mark the last hour of the night (dawn) of the
36 Egyptian decades through their heliacal rising. This phenomenon was known in
later sources as prt, going forth, or ms, birth (Clagett 1995). This is the list that we
analyse in this work, imposing a series of premises which can be ascertained from
the original sources. These are that the decans should belong to the Southern Sky
(they are called southerners), they should rise in the Southeast or near there (together
with the sun in the land of Punt) and they should stay in the Duat for 70 days. This
last premise probably meant that they were lost in the sun glare for that period and,
in my opinion, it should not be interpreted in a very restrictive way (as N&P did);
the theoretical period being originated for the period of invisibility of Sirius, the
head of the decans, in Middle Egypt in the second half of the 3 rd Millennium BC.
Finally, we believe that the decans should have been, predominantly, prominent
stars or asterisms. Taking all these facts into account, we have made the following
approach to the problem:






First, we tried to produce a series of stars separated by approximately 10º of
ecliptic longitude starting by Sirius, which normally had been interpreted as the
decan star spd. However, this idea did not work properly in our opinion since,
among other examples, the constellations Sah would have extended then as far
as the Pleiades.
We then used the Gotto Planetarium of the Museo de la Ciencia y el Cosmos de
Tenerife to observe which prominent stars and asterisms would have been rising
in the SE in 10 day intervals for various latitudes and epochs, allowing an
average error of one day. We started again with Sirius. The results are
summarised in Table 1 where we present the results for the latitudes of
Memphis, Thebes and Asswan for 2200 BC and, for checking, for Middle
Egypt in 2800 BC.
At this moment, we realised that the decan spd (Triangle) could also be found
in the sky (see Figures 2 & 3) in the same way as the decan sAH had been
suggested by Locher (2001). We then will continue using that idea in all the
following arguments, considering that Sirius (Sepedet) was just one star more of
the asterism of the Triangle. This situation might have changed in later sources,
specially when the system was converted in a transit device, and when this
decan was normally written [ ] (i.e Sepedet or Sirius).
Then we proceed to calculate the dates of the heliacal rising of all these stars
trying to fit then in a 10 day interval scheme, for 2200 BC and different
latitudes, starting not by the heliacal rising of Sirius but of all the Triangle
(spd), represented by the fainter star CMa. The results are summarised now in
Table 2 and , from my point of view, they offer extremely suggestive
possibilities, specially for the area between Sirius (or better the Triangle) and
the Pleiades (see Figure 3).
To further identify the rests of the decan stars, we had to impose a new criterion
to answer the question: what is the frontier between the Egyptian southern and
northern skies? According to Krauss (1997 and private communications), the
frontier could be the Ecliptic, interpreted by him as the “winding water way”
(this is much surer for the frontier between the Filed of reeds and the Field of
Offerings of the Pyramid Texts).
However, Davis (1985) has suggested that the frontier might also be the Milky
Way, identified by Wells (1994) with goddess Nut whom, in several ceilings is
represented in the middle of the sky. Considering that later possibility, we have
proposed our list of decans presented in Table 3 and illustrated in Fig. 3 and 4.
One result of our proposal is the impossibility of following several of Locher’s
identification of the ancient Egyptian constellations. Although the Circle (kd)
would be effectively the Head of Cetus, for us the Sheep (srt) should be
located in Grus (or Piscis Austrinus) and the Boat (wiA) should be identified
with Capricornus (constellation which, in fact, resembles the form of an ancient
Egyptian boat). The Front (xntt) is still in Scorpio but we are not sure of its
identification with the Prow of the boat. We specially regret the apparent
impossibility of identification of Antares with the Red of the Front (Tms n
xntt).
 In order to text our ideas, we also tried to fit the pattern with the later
representations of the decans of the New Kingdom, taking the ceiling of
Senmwt tomb as an example where the system is, apparently, a heliacal rising
device yet. Here we have considered Ast spdt as Sirius and not as all the
Triangle. The results are summarised in Table 4 and we can see that the system
still adjusts reasonably but not in every feauture.
 The analysis of the “Book of Nut”, where, almost surely, we are dealing with a
meridian transit system based upon the decans, developed perhaps in the Middle
Kingdom (c. 1850 BC) when the heliacal rising system started to give problems
(see N&P or Clagett, 1995), will be left for future works. This is because we
believe that it deserves a longer discussion, in connection to the Ramesside star
clocks (Clagett, 1995; Belmonte, 2001).
 Finally, our proposal was tested with the decans represented in the ceiling of
the Hipostyle Hall of the Temple of Hathor in Denderah (c. 50 BC). In this
epoch, the decans were almost surely areas of 10º along the Ecliptic, associated
to the zodiacal signs, and there should be few connections with the original
decan stars selected for the diagonal clocks more than 2000 years earlier. As
demonstrated in Table 5, this seems to be the case since several proposals are
problematic but still some previous identifications would be operative (see, for
example, the Pleiades and the Hyades like xAw and art, respectively). These
would be the last signatures of a former glorious past.
One final hypothesis, resulting from the analysis, would be that ancient Egyptian
skylore, referenced for the first time in written sources in the Pyramid Textxs (c.
2350 BC), would have inspired the creation of the decanal system somewhere in the
Middle Egypt around 2200 BC, perhaps during the poorly known period of rule of
the Hereacleopolitan dynasties.
Figure 4: The southern sky with the
approximate locations proposed for
the rest of the 36 decans of the coffin
lids (see Table 3) and the most
important constellations, the Circle
(head of Cetus) the Sheep (area of
Grus and Piscis Austrinus), the Boat
(Capricornus) and the Front (area of
Scorpius). This figure complements
Figure 3. In our proposal, the decan
wS3t bk3ti
(i.e. the Sothern Cross) was later
divided into two, the Twins (wsAti,
 &  Cru) and the Two Pregnants
(bkAti,  &  Cru).
Table 1: The decans identified by numbers (see Table 3) and the stars rising on
intervals of decades for 2800 BC at Middle Egypt and for 2200 BC at Memphis,
Thebes and Asswan.
N
1
2
3
4
5
6
26ºN 2800 BC
30ºN 2200 BC
23½ºN 2200 BC
25½ºN 2200 BC
Phact or Adhara
Phact or Adhara
Phact or Adhara
Adhara or Columba
CMa or Columba
CMa or Columba
CMa or Columba
Cma or Columba
Dove’s leg or Pup
Dove’s leg or Pup
Dove’s leg or Pup
Dove’s leg or Pup
 Velae or .....
 Velae or
Alsuhail
Canopus or Alsuhail
Canopus or Alsuhail
Alsuhail (Car)
Canopus or Regor
 Velae or 1st False Crux
 Velae (1ª False Cross) or....
False Cross: Vel, Car,Vel
False Cross
7
8
9
10
11
12
13
14
15
False Cross (Car,Vel, Car)
Vel & Car
Canopus
Vel & Car
False Cross (Car), Car
Some of Argo or Cen
Cen or Gacrux
Cen or Gacrux
Cen
Cen & Gacrux
Crux or Cen
Crux or Cen
Crux
Crux
Cen & ¿Cen?
Cen
Cen
Cen & Cen
Cen & Antares
Cen & Antares
Cen
Antares or ... (Lup, Cen)
Sco, Sco, Sco or ...
Sco, Sco, Sco or ...
Sco, Sco & Antares or ...
Sco, Sco, Sco or ...
Sco, Ara or Tri
Sco, Ara or Tri
Sco or Tri
Sco, Ara or Tri
Sag or Sag or ...
Sag or ...
Sag & Sag or ...
Sag or Sag or ...
Corona Australis
Sag & Sag or Cor Aus
Cor Aus or Sag & Sag
16
17
18
19
20
Some of Pavo
Cor Aus or Sag &
Sag
Some of Pavo or Sag
Sag & Sag
Pavo
Pav or some of Cap
Pav or some of Cap
Pav or some of Cap
Pav or some of Cap
Cap, Ind or Mic or Mic
Mic or Mic
Mic or Mic
PsA & Psa (Sheep)
Gru or PsA
Gru
Gru or PsA
Gru or oPsA
Gru (h & X Per)
Gru (h & X Per)
Gru (h & X Per)
21
22
23
24
Fomalhaut or 1 & 2 Gru
1& 2 Gru (h & X
Per)
Gru & Fomalhaut
Fomalhaut or 1 & 2 Gru
Fomalhaut or 1 & 2 Gru
Gru
1 & 2 Gru
Gru
Gru
Pho or Cet (south of Psc)
Gru
Gru or ....
Pho, Cet or Gru & Gru
Diphda (Deneb Kaitos) or ...
Pho or a faint of Sculptor
Diphda (Deneb Kaitos)
25
26
27
28
Diphda or ...
Pho or a faint of
Sculptor
Diphda (Deneb Kaitos)
Diphda (Deneb Kaitos)
Cet or  &  Cet
Cet or  &  Cet
Cet or  &  Cet
Cet or  &  Cet
Point of Pentagon
Cet or ¿Mira?
Cet (Pentagon)
Cet (Pentagon)
Mira or Point of Pentagon
Mira, Pleiades, Pentagon
Menkar (Penta) & Pleiades
Menkar & Pleiades
29
30
Menkar (Pentagon)
Menkar (Penta)
Pleiades
Tau & Tau
Tau or ....
Tau & Tau (Hyades) or ...
Aldebaran & Hyades
Aldebaran & Hyades
31
32
Arch of Ori
Aldebaran & rest of
Hyades
Arch of Ori
Arch of Ori
Arch of Ori
Bellatrix & base of the arch
Bellatrix & base of the arch
33
Alnitak, Mintaka, Ori, Eri
Alnitak, Mintaka, Ori, Eri
Belt, Ori, Rigel
34
Alnilam, Rigel, M42, M44
Alhilam, Rigel, M42, Saiph
Saiph
35
36
Saiph or Lep
Bellatrix & base of the
arch
Alnitak,
Mintaka,
Ori, Eri
Alnilam, Rigel, M42,
M44
Saiph or Lep
Lep or Cma
Between Lep & CMa
Sirius
Sirius
Sirius
Sirius or Phact
Aldebaran & Hyades
Bellatrix & base of the arch
or
&
Table 2: The 36 decans of the diagonal star clocks: probable identification by places (c. 2200 BC).
N
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
Coffins (D. IX to XI)
knmt
s3wy knmt
Xry xpd knmt
h3t x3w
phwy x3w
Tm3t Hrt
Tm3t Xrt
wS3t bk3Ti
ipDs (sSpt)
sbSsn (tpya xntt)
xntt Hrt
xntt Xrt
Tms n xntt
kdty (s3pti xnwy)
xnwy
Xry-ib wi3
--4 persons-- (Ssmw)
knmw (tpya smd)
smd srt
srt
s3wy srt
Xry xpd srt
tpya 3xwy
3xwy
imi xt 3xwy
b3wy (or xntw)
kd
x3w
ar(y)t
Xry ar(y)t
rmn Hry s3H
rmn Xry s3H
abwt
Xrt wart
tpya spd
Date
16/07
27/07
06/08
16/08
26/08
05/09
15/09
25/09
06/10
16/10
26/10
05/11
15/11
25/11
05/12
16/12
26/12
05/01
15/01
25/01
04/02
14/02
25/02
07/03
17/03
27/03
06/04
16/04
26/04
07/05
17/05
27/05
06/06
16/06
26/06
36
spd (tpya knmt)
06/07 (5±3/7) CMa (4.1) 
11/07
spdt
(22±6/6) Sirius (-1.5)
(*): (16±12/8) Car (-0.7)
(**): (26±4/5) Ori (0.5)
Middle Egypt (27º)
(12±4/7)  CMa (1.5)
(28±4/7) Pup (2.7)
(4±5/8) Pup (2.2)
(14±5/8) Vel (1.8) (*)
(27±5/8) Vel (2.0)
(7±5/9) Car (2.2)
(12±5/9) Car (¿.?)
(23±4/9) Cru (1.6)
(4±4/10) Cen (0.6) & Crux
(13±3/10) Cen (0.0)
(28±1/10) Sco (2.3)
(6±1/10) Sco (1.6)
(15±1/11) Sag (3.0) M8
(24±1/11) Sag (2.0)
(5±2/12) y Sag (4.0)
(16±1/12) /Cap (3.6/3.1) ?
(25±4/12) Ind (3.1) ?
(7±1/1) /Cap (3.7/2.9) ?
(16±4/1) Gru (3.0)
(29±10/1) Gru (1.7)
(4±5/2) PsA (1.2)
(16±12/2) Gru (2.1)
(23±8/2) Scr (4.5)
(18±18/3) Scr (4.5)
(14±5/3) Cet (2.0)
(22±5/3) Cet (3.4)
(8±3/4) Cet (4.3)
(16±2/4) Pleiades (2.9)
(30±4/4) Tau (0.8) Hyades
(6±2/5) Tau (3.4) Hyades
(14±3/5) 88/90Tau (4.2/4.3)
(28±3/5) 6Ori (4.5) (**)
(4±5/6) Ori (0.1) Belt
(13±4/6) Ori (2.1) or Lepus
(26±4/6) CMa (2.0)
Date
21/07
02/08
12/08
22/08
01/09
11/09
22/09
02/10
12/10
22/10
01/11
11/11
21/11
01/12
11/12
21/12
31/12
10/01
20/01
31/01
10/02
20/02
02/03
12/03
22/03
01/04
11/04
21/04
02/05
12/05
22/05
01/06
11/06
21/06
01/07
Memphis 30º
(16/7)  CMa (1.5)
(1/8) Pup (2.7)
(9/8) Pup (2.2)
(19/8) Vel (1.8)
(1/9) Vel (2.0) [Car (29/8)]
(12/9) Car (2.2)
(16 a 24/9) Car (1 a 5)
(2/10) Cru (1.6) All Crux
(8/10) Cen (0.6)
(21/10) Sco (1.0) Cen (16)
(1/11) Sco (3.1)
(7/11) Sco (1.6)
(18/11) Sag (1.8) M8
(2/12) CrA (4.0)
(7/12) y Sag (4.0)
(16/12) /Cap (3.6/3.1)
(27/12) Cap (4.1) Ind (29)
(9/1) Cap (2.9)
(20/1) Gru (3.0)
?
(9/2) PsA (1.2) Gru (8)
(18 to 21/2) 1/2 Gru (4/4.1)
(1-4/3) Gru-Scr (2.1-4.3)
?
(20/3) Cet (2.0)
(27/3) Cet (3.4)
(11/4) Cet (4.3)
(18/4) Pleiades (2.9)
(4/5) Tau (0.8) Hyades
(9/5) Tau (3.4) Hyades
(22/5) ³Ori (3.2)
(1/6) Ori (0.5) & 6Ori (4.5)
(9/6) Ori (0.1) Belt
(17/6) Ori (2.1) or Lepus
(1/7) CMa (2.0)
Date
13/07
23/07
02/08
12/08
22/08
01/09
11/09
22/09
02/10
12/10
22/10
01/11
11/11
21/11
02/12
12/12
22/12
01/01
11/01
21/01
31/01
11/02
21/02
03/03
13/03
23/03
02/04
12/04
23/04
03/05
13/05
23/05
02/06
12/06
22/06
Aswan 23½º
(8/7)  CMa (1.5)
(23/7) Pup (2.7)
(31/7) Pup (2.2)
(9/8) Vel (1.8) Car (4)
(22/8) Vel (2.0)
(1/9) Car (2.2)
(7 a 14/9) Car (1 a 5)
(22/9) Cru (1.2) Top of Crux
(1/10) Cen (0.6)
(10/10) Cen (0.0)
(19/10) Sco (1.0)
(1/11) Sco (3.6)
(14/11) Sag (3.0) ? M8
(18/11) Sag (2.7)
(30/11) CrA (4.0)
?
(21/12) Ind (3.1) ?
?
(12/1) Gru (3.0)
(19/1) Gru (1.7)
(29/1) Gru/PsA (2.8/1.2)
?
(15-21/2) Scr-Gru (4.5-4.3)
(28/2) Scr (4.5)
(9/3) Cet (2.0)
(17/3) Cet (3.4)
(5/4) Cet (4.3) ¿?
(12/4) cet (3.5) Tau (15)
(26/5) Tau (0.8) Hyades
(4/5) Tau (3.4) Hyades
(11/5) 88/90Tau (4.2/4.3)
(21-23/5) Ori-6Ori (0.5-4.5)
(31/5) Ori (0.1) Belt
(9/6) Ori (2.1) or Lepus
(22/6) CMa (2.0)
(9/7) CMa (4.1) 
Sirius (26/6)
02/07
(2/7) CMa (4.1) 
Sirius (19/6)
Table 3: Identification of the Decans of the Star Clocks. The table presents, for each decan, a
number, its hieroglyphic name and transliteration, our proposed translation and suggested
identification (with average magnitude mv and declination  for 2200 BC), the number of
days of invisibility (time in the Duat) and, finally, the degree of confidence that we have in
the proposed identification.
N
DECANS
Coffins
(D. IX-XI)
Translation
Star/Asterism
1
knmt
 CMa and back
of CMa
Cow
2
Days

877
4
1007
4
988
4
10710
3
1157
3
11610
2
1018
2
9810
5
978
4
989
4
464
4
614
3
584
3
553
1
473
3
756
3
766
3
381
3
584
3
1.5
-28
2.7
s3wy knmt
Pup & ....
Cow Twins
-36
2.2
3
Xry
xpd knmt
Under the Tail
of the Cow
Pup
Front of Myriad
Vel
[or Car (-0.7)]
4
h3t x3w
5
phwy x3w
Back of Myriad
6
Tm3t Hrt
Tm3t Xrt
Car
Lower Zmat
(Wing)
Car
The Twins &
the 2 Pregnants
Southern Cross
(, ,  & Cru)
Its own count
(Luminous)
Cen or Part
of Crux
Sage’s Star
Cen (or Cen)
9
ipDs
(sSpt)
10’
sbSsn
-41
2.0
-44
2.2
-46
1.5
-44
1.6
8
wS3t bk3ti
-34
1.8
Vel
Upper Zmat
(Wing)
7
-37
0.6
-37
0.0
-39
1.0
10”
tpya xntt
Head of the Front
(or Prow or South)
Sco (or Cen)
Upper of the Front
(or Prow or South)
Sco or .....
Lower of the front
(or Prow or South)
Sco
Red of the Front
(of Prow or South)
Sag & ...
(with M8)
2 Circles
Sag with CrA
11
xntt Hrt
xntt Xrt
-22
3.0
13
Tms n xntt
14’
kdty
-08
2.3
-20
1.6
12
-13
2.0
-30
4.0
14”
s3pti xnwy
Khanuy’s Net
15
xnwy
2 Khanuy Fishes
16
Xry-ib wi3
17
1: Speculative
sure
mv
-4 persons(Ssmw)
2: Likely
Heart of the Boat
CrA with
Sag & Sag
Sag & Sag
Cap & Cap
-30
4.0
-34
3.6
-17
4.0
Crew?
(Winepress?)
3: Probable
Cap & ....
4: Highly probable
-30
5:
Almost
N
DECANS
Coffins
(D. IX-XI)
Translation
Star/Asterism
knmw
Secret Stars ?
Cap & .....
18’
mv
Days

452
3
7810
2
849
2
12420
3
12210
3
12020
2
10015
1
12214
1
857
2
726
1
726
1
603
4
422
5
435
5
542
5
634
4
733
4
756
5
766
3
817
5
827
5
2.9
-26
4.3
18”
tpya smd
Head of Horn
19
smd srt
Horn of the Sheep
20
srt
Sheep or Goat Star
PsA
Gru
Gru
-41
3.0
-46
1.7
-55
2.8
21
s3wy srt
Sheep Twins
22
Xry xpd srt
1/2Gru or
PsA (1.2/7210)
Under the Tail
of the Sheep
Gru
Head of the
Two Spirits
Scr
The Two Spirits
Scr
-53
4.5
23
tpya 3xwy
24
3xwy
25
imi xt 3xwy
Favourite of the
Two Spirits
Cet
The Two Souls
Cet or ...
-44
4.5
-46
2.0
-31
3.4
26’
b3wy
-44
2.1
-26
3.4
26”
xntw
“Khentu”
27
kd
Cet or ...
Circle or
Sheepfold
Cet & the
Pentagon of Cetus
Myriad or Flock
Pleiades
28
x3w
-26
4.3
-15
2.9
04
0.8
29
ar(y)t
Jaw
(or Rising Stars)
Tau & Hyades
Lower Jaw
Tau
(Lower Hyades)
30
Xry
ar(y)t
31
rmn Hry s3H
Upper Arm of Sah
32
rmn Xry s3H
Lower arm of Sah
Between 88/90Tau
& 3Ori
6Ori or
Ori (0.5/537)
33
abwt
(sAH)
Trident or Sceptres
(Sah)
Ori and the Belt
Xrt wart
Lower Leg
Ori (or Lep)
34
35
tpya spd
Before the Triangle
CMa
00
3.4
00
3.2
-03
4.5
-06
0.1
-17
2.1
-20
2.0
-25
4.1
36
spd (tpya knmt)
Triangle
(Cow Head)
CMa & the 
[Sirius (-1.5/666)]
-20
Table 4: Heliacal risings in the New Kingdom and the decans in the ceiling of the tomb of Senmwt. The table
presents the 36 original decans that we have used in the analysis and compares them with those found in the ceiling.
5th and 6th columns propose heliacal rising dates and possible identification for those later decans, respectively. It is
obvious that the system was not working properly already for this epoch.
N
1
2
3
4
5
6
7
8
9/10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29/30
31
32
33
34
35
36
36 original decans
knmt
s3wy knmt
Xry xpd knmt
h3t x3w
phwy x3w
Tm3t Hrt
Tm3t Xrt
wS3t bk3ti
Senmwt
tpya knmt (0)
knmt (I)
Xry xpd knmt (I)
h3t D3t (II)
phwy D3t (II)
Tm3t Hrt (III)
Tm3t Xrt (III)
wS3ti (IV)
bk3ti (IV)
(1)
ipDs & sbSsn
tpya xntt (V)
xntt Hrt
xntt Hrt (V)
xntt Xrt
xntt Xrt (wi3)
Tms n xntt
Tms n xntt (wi3)
kdty
s3pti xnwy (wi3)
xnwy
(2)
Xry-ib wi3
Xry-ib wi3 (wi3)
Ssmw (wi3)
“4 Persons”
knmw
knmw (wi3)
smd srt
tpya
smd / smd
(srt) (3)
srt
sit
(3-nwt
Xt)
(srt)
s3wy srt
s3wy sit (srt)
Xry xpd srt
Xry xpd srt
tpya 3xwy
tpya 3xwy
3xwy
3xwy
imi xt 3xwy
b3wy (Xt 4-nwt)
b3wy or xntw
xntw Hrw & xntw
Xrw (VI)
kd
kd & s3wy kd (VII)
x3w
x3w (Xt 5-nwt)
ar(y)t & Xry art (4)
ar(y)t
rmn Hry s3H
rmn Hry s3H
rmn Xry s3H
rmn Xry s3H
abwt
s3H ( Xt 6-nwt)
Xrt wart
ah s3h
tpya spd
spd
3st spdt
N
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Date
18/07
29/07
08/08
18/08
28/08
07/09
17/09
27/09
08/10
18/10
28/10
07/11
17/11
27/11
07/12
18/12
28/12
07/01
17/01
27/01
Heliacal rising 1500 BC 25½º
(16/7)  CMa ?
(30/7) Pup ?
(8/8) Pup
(16/8) Vel (11/8) Car
(30/8) Vel
(3/9) Car
(17/9) Car
(26/9) Cen (1/10) Cru
(6/10) Cru (Crux)
(14 & 22/10)  & Cen
(29/10) Sco
(7/11) Sco
(16/11) Sco
(25/11) Sag ?
(3 & 7/12) Sag & Sag ?
(16/12)  & Sag
(24 & 25/12)  & Cap
(6/1) Ind (5/1) Cap ?
(18/1)  & Cap ?
(25/1) PsA / (29/1) Gru ?
21
06/02
(11/2) Gru ?
22
23
24
25
26
27
16/02
27/02
09/03
19/03
29/03
08/04
(14/2) PsA
(20 a 22/2) 1 & 2 Gru ?
(5/3) Scr ?
(22/3) Scr ?
(29/3) Cet
?
28
29
30
18/04
28/04
09/05
(16/4) Cet
(25/4) Pleiades
(6/5) Tau (Hyades)
31
32
33
34
19/05
29/05
08/06
18/06
(20/5) 90Tau
(28/5) Ori / (31/5) Ori
(9/6) Ori (Belt)
(17/6) Ori
35
28/06 (28/6) Sirius
36
08/07 (10/7) CMa (11/7) Col ¿?
(0). Some misplacings might have been produced. These decans, (I) to (VII), are found in pairs in the same column.
(1): sSpt (Cen?) & sbSsn (Cen?) are found among the triangular decans. (2): Between s3pti xnwy & smd
there are loses and changes of several stars and decans.
(3): Together in the same box.
(4) The position of the following 5 decans has been altered.
Table 5: Transit Decans of the ceiling at the Hipostyle Hall in Denderah, dating c. 50 BC. The table presents the
36 original decans that we have used in the analysis and compares them with those found in the Denderah ceiling. 5 th
and 6th columns propose the expected right ascension (error of ±0.2 hours) and hypothetical identification for those
later decans, respectively. At this time, the decans have been already converted in 10º sectors of the zodiacal signs
(column 77h) with little connection to the original decan stars. Notice the possibility of identification of Tms n xnt
with Antares which did not work for earlier times when the decans were part of a heliacal rising device.
N
36 decans
Hipostyle Hall
N
Sign
 (h) 50 BC at 26º
knmt
St

1
2
6.6
Pup (6.8) ?
s3wy knmt
knm

2
3
7.2
Vel (7.1)
Xry
xpd xnt Xry

3
4
7.9
Vel (7.9) or Vel (7.8)
knmt
h3t x3w
h3t D3t

4
5
8.6
?
phwy x3w
phwy D3t

5
6
9.2
?
Tm3t Hrt
tm3t

6
7
9.9
Car (9.5) ?
Tm3t Xrt
7
wS3t bk3ti wS3tbkti

8
8
10.6
Cru/Cru (10.5/10.6)
ipDs

9
11.2
ipts (Its own count, 9
Cru (11.0)
Harem?)
sbSsn

10
10
11.9
sbhs (Faint Star) (1)
Cen (12.0)
tpya xntt

11
12.6
Cen (12.5 ) ?
xntt Hrt
xnt Hrt

11
12
13.2
?
xntt Xrt
xnt Xrt

12
13
13.9
Sco (14.2) ?
Tms n xntt Tms n xnt

13
14
14.6
Sco (14.5) ?
kdty
14
xnwy
spti xnwy

15
15
15.2
Sco (15.3) ?
hry-ib wi3 Xry-ib wi3

16
16
15.9
Sag (15.9) ?
Ssm

17
“4 Persons”
17
16.6
Sag (16.8) ?
knmw
knm

18
18
17.3
Sag/CrA (17.0/17.1) ?
tpya smd

19
17.9
Ind (17.9)
smd srt
smd

19
20
18.6
 Cap (18.6)
srt
srt

20
21
19.2
Gru (19.4) or some in Cap
s3wy srt

21
22
19.9
s3 srt (Little sheep)
Cap (19.9) - 1/2Gru (20.2)
Xry
xpd Xry xpd srt

22
23
20.6
Gru (20.4) ?
srt
tpya 3xwy
tpya 3xw
23
24
21.2
PsA/Gru (20.9) Scr (21.3) 
3xwy
3xw

24
25
21.9
Scr (21.5)
imi
xt
25
3xwy
tpya b3wy

26
22.6
Pho (22.6) ?
b3wy
b3w

26
27
23.2
Cet (23.4) ?
xnt Hr

28
23.9
Cet (0.1) ?
xnt Xr

29
0.6
Cet (0.6)
kd
27
s3 kd

30
1.2
Cet (1.2)
x3w
x3w

28
31
1.9
Pleiades (1.9)

29/3 ar(y)t
32
2.6
& art
Tau & Hyades (2.4/ 2.7)
0
Xry
ar(y)t
rmn
Hry rmn Hry

31
33
3.2
6Ori (3.3)
s3H
rmn
Xry
32
s3H
abwt

33
34
3.9
Ts ark (Bow)
Ori & Belt (3.9)

Col (4.4)

Sirius (5.2) or CMa (4.9)
CMa () (5.5) or CMa 
(6.0)
(1): There is also a a3 phty rhn pt t3 (Bridge between Heaven and Earth).
34
35
36
Xrt wart
tpya spd
spd
wart (Leg)
tpya spdt
spdt
35
36
1
4.6
5.2
5.9
Acknowledgements
It is a pleasure for me to acknowledge the Organisation of INSAPIII for providing a
marvellous environment to discuss about Astronomy and Culture and, specially, Prof.
Giorgia Fodera’-Serio for her encourage and support. Thanks are also due to Dr. Miguel
Angel Molinero, Egyptologist of La Laguna University, for interesting discussions which
have greatly improved large parts of the paper. Part of this work is a result of the 5 year
directorship of the author at the Museo de la Ciencia y el Cosmos, with easy access to the
Planetarium. This work has been partly financed by the IAC under the project P7/93
Arqueoastronomía.
References
Belmonte, J.A.: 1999, “Las Leyes del Cielo”, Temas de Hoy, Madrid.
Belmonte, J.A.: 2000, “Astronomía y arquitectura: el papel de los astros en la cultura y el arte
del antiguo Egipto”. In Arte y Sociedad del Antiguo Egipto, Molinero M.A. & Sola D.
(Eds.), Encuentro, Madrid.
Belmonte, J.A.: 2001, “The Ramesside star clocks and the ancient Egyptian constellations”.
In Proc. SEAC 2001 Meeting on Symbols, calendars and orientations, Stockholm, August
27-30. In press.
Böker, R.: 1984, “Über Namen und Identifizierung der ägyptischen Dekane”, Centaurus 27,
189-217.
Bomhard A.S., von: 1999, “The Egyptian calendar: a work for eternity”, Periplus, London.
Clagett, M.: 1995, “Ancient Egyptian Science. Volume II: Calendars, clocks and astronomy”,
American Philosophical Society, Philadelphia.
Davis, V.L.: 1985, “Identifying ancient Egyptian Constellations”. Archaeoastronomy
Supplement. J.H.A, 9, S102-104.
Faulkner, R.O.: 1969, “The Ancien Egyptian Pyramid Texts”, Oxford University Press.
Gallo, C.: 1998, “L’astronomia egizia”.,Franco Muzzio Ed., Padova.
Haack, S.C.: 1984, “The Astronomical orientation of the Egyptian Pyramids”.,
ArchaeoastronomySupplement. J.H.A,. 7, S119.
Hawkins, G.S.: 1973, “Beyond Stonehenge”, Harper & Row, New York.
Hawkins, G.S.: 1975, “Astroarchaeology: the Unwritten evidence”. In Archaeo-astronomy in
Pre-columbian America, A.Aveni (Ed.), Austin Univ. Press., 131-162.
Krauss, R.: 1997, “Astronomische konzepte und jenseitsvorstellungen in den
pyramidentexten”, Ägyptologische Abhandlung, 59, Wiesbaben.
Krupp, E.C.: 1977, “In search of the Ancient Astronomers”, Dubleday & Co., 208-219.
Krupp, E.C.: 1984, “Egyptian Astronomy: Temples, Traditions, Tombs”. In
Archaeoastronomy and the Roots of Science, AAAS Sym. 71, Westview Press Inc.
Krupp, E.C.: 1991, “Beyond the blue horizon”, Oxford University Press.
Leitz, C.: 1991, “Studien zur Ägyptischen Astronomie”. “Afyptologische Abhandlungen, 49,
Otto Harrassowitz (Ed.), Wiesbaden.
Locher, K.: 1981, “A conjecture concerning the early Egyptian constellation of the Sheep”,
Archaeoastronomy Supplement J.H.A,. 3, S63-S65.
Locher, K.: 1985, “Probable identification of the ancient Egyptian circumpolar
constellations”, Archaeoastronomy Supplement J.H.A,. 9, S152-153.
Locher, K.: 2001, “New arguments for the celestial location of the decanal belt & the origins
of the sAX hieroglyph”, Proc. Oxford V Conference on Cultural Aspects of Astronomy.
Santa Fe.
Lockyer, J.N.: 1894, “The Dawn of Astronomy”, McMillan, New York and London.
Reprinted in 1993 by Kessinger Co. Edit.
Neugebauer, O.: 1969, “The exact sciences in antiquity”, Dover Inc. Pub.
Neugebauer, O. & Parker, R.A.: 1960-69, “Ancient Egyptian Astronomical Texts”, Three
Volumes, Brown University Press.
Parker, R.A.: 1950, “The Calendars of Ancient Egypt”, Chicago Univ. Press.
Petrie, W.M.F.: 1940, “Wisdom of the Egyptians”, London.
Roy, A.E.: 1882, “The Astronomical Basis of Egyptian Chronology”, Soc. for
Interdisciplinary StudiesRewiew, 6, 53-55.
Sellers, J.B.: 1992, “The Death of Gods in Ancient Egypt”, Penguin Books.
Spence, K. 2000, “Ancient Egyptian chronology and the astronomical orientation of
pyramids”, Nature, 408, 320-324.
Wells R.A. 1994, “Re and the Calendars”. In Revolutions in Time: studies on Ancient
Egyptian Calendrics, Spalinger A.J. (Ed.), Van Sieclen Books.