NOTES FOR STAR-OF-BETHLEHEM
-------------------------
John Pazmino
NYSkies Astronomy Inc
www.nyskies.o
nyskies@nyskies.org
2002 December 21
[Dates are Julian Universal Time. Dates may differ slightly from
other calcs due to algorithms and definitions]
year date event
------- ------ --------------------
early birth events
------------------
7BC, -6 May 29 Jupiter-Saturn conjunction
Jul 7 Saturn western station
Jul 17 Jupiter western station
Sep 14 Saturn opposition
Sep 15 Jupiter opposition
Sep 30 Jupiter Saturn conjunction
Nov 12 Jupiter eastern station
Nov 20 Saturn eastern station
Dec 12 Jupiter-Saturn conjunction
6BC, -5 Feb 20 Moon-Mars conjunction
Moon-Jupiter conjunction
Moon-Saturn conjunction
Moon-Mars-Jupiter-Saturn convention
Mars-Saturn conjunction
Mar 4 Mars-Jupiter conjunction
Mar xx nova in Aquila-Capricornus
Apr 17 Moon-Jupiter occultation
Jul xx nova in Cygnus [these MAY be rally a comet moving
from Capricornus to Cygnus, lasting 70 days, OR
nova misplaced but still lasting 70 days]
Aug 22 Jupiter western station
Oct 21 Jupiter opposition
Nov 16 Jupiter eastern station
Herodus's events
----------------
4BC, -3 Mar 13 partial lunar eclipse
1BC, 0 Jan 10 total lunar eclipse
1BC 0 Dec 29 partial lunar eclipse
late birth events
-----------------
4BC, -3 May 18 Venus-Mars conjunction
May 24 Venus-Jupiter conjunction
May 24 Venus-Mars-Jupiter convention
May 31 Mars-Jupiter conjunction
3BC, -2 Aug 11 Moon-Venus-Jupiter convention
Aug 12 Venus-Jupiter conjunction
Sep 13 Jupiter-Regulus conjunction
Nov 27 Jupiter western station
2BC, -1 Jan 26 Jupiter opposition
Feb 18 Jupiter=Regulus conjunction
Mar 29 Jupiter eastern station
May 7 Jupiter-Regulus conjunction
Jun 17 Jupiter-Venus consolidation
Aug 31 Moon-Venus-Mars-Jupiter convention
modern events (Gregorian dates)
------------------------------
1779AD Nov 9 Mira brightest maximum of 1.3 magnitude
1972AD xxx xx Enif flareup to 0.9 magnitude
1980AD Dec 31 Jupiter-Saturn conjunction
1981AD Jan 2 JUpiter western station
Jna 18 Saturn western station
Jan 24 Jupiter western station
Mar 4 Jupiter-Saturn conjunction
Mar 26 Jupiter opposition
Mar 27 Saturn opposition
May 27 Jupiter eastern station
Jun 5 Saturn eastern station
Jul 24 Jupiter-Saturn conjunction
1994AD Jul xx Jupiter-SL9 collision
1998AD Apr 23 Moon-Jupiter occultation, with Venus
Apr 23 Moon-Venus occultation, with Jupiter
2000AD Feb xx Dschubba flareup to 1.8 magnitude
[Not exhaustive, but I touched the important points]
Years are numbers in the BC era in two ways. The historical or
chronological method starts with '1BC' for the year preceding 1AD. The
numbering continues backwards into the past from there. There is NO
year number '0'.
The astronomical or algebraic method counts with a year '0' and
past years are negative numbers. Lo here the timeline for comparison.
-7 -6 -5 -4 -3 -2 -1 0 1 2
>--|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-->
8BC 7BC 6BC 5BC 4BC 3BC 2BC 1BC 1AD 2AD
Note that the 'BC' year is one GREATER in absolute value than the
'minus' year. You MUST understand how your planetarium program treats
years in the BC era to set it correctly for Christmas Star
simulations.
I don't know, and can't find any one who knows, why AD is Latin
and BC is English. I have seen 'AC' for 'ante Christo' for BC years.
The calendar in force across the BC/AD period was the Julian, not
Gregorian, calendar. The contemporary calendar was a bit out of joint
from political tampering and lack of modern concepts of 'history'. All
dates are now established by a copasetic Julian calendar.
For studies before the Julian calendar (about -45 or 46BC) we
prolong the Julian calendar backwards, even tho the 'date' is then
entirely fictitious. That's why you can read of some Japanese eclipse
on, made up, 1234BC January 8, when there simply was no such a date in
existence so far long ago.
The days of the week are generally missed out in the BC era for
astronomy purposes. However, the week cycles thru the seven days
without interruption or shuffling regardless of what happens to the
calendar date.
Planetarium programs MUST have longterm dynamics for the planetary
motions and precession. Using a program with 'trolley track' orbits
and a simple precession will yield erroneous simulations. Some
programs specify the range of valid years; HNSky, for instance, will
NOT work for years before 1750. Others don't trap invalid dates but
will then display all wrong skies.
The program MUST be fed contemporary comet orbit elements. You can
NOT just change the perihelion date of a modern orbit.
SkyMap, Starry Night, Dance, SkyGlobe, Expert Astronomer are
examples of good planetarium programs.
Jerusalem is at latitude 31 degrees north, longitude 48 degrees
east, rounded. A shift eastward in longitude only affects the hour of
a sky display. You may pick from your planetarium's city list any
place in Israel, Jordan, Iraq, or Iran. These modern countries are in
the path presumably taken by the Magi, who likely (but hardly
certainly!) came from either Babylonia or Persia.
The delta-T correction, the offset of Universal Time from the
Atomic Time, may be ignored. Your planetarium may work with a lookup
value or may be lack a delta-T feature.
The one and only account of the Star is in book of Matthew. There
is no other independent record of the Star, only commentary based on
Matthew. Matthew does not say anything about:
the brilliance of the Star
the size, shape, changes of the Star
which segment of the day the Star was seen
how many Magi came to Bethlehem
where specificly the Magi came from
the time frame for the Magi's trip
Any assertions about these features comes from external
considerations, not as yet certainly founded in history.
The Star could be a single celestial event or a series of events.
It may be an interpretation of some reproducible predictable event, or
one which was unpredictable and now nonreproducible.
On the other hand the Star could be a truly other-worldly
apparition or a total fabrication.
Astrology may be a weak feature in the Christmas Star story
because the magi were basing their trip on the Jewish scriptures and
Jewish faith. Faithful Jews did not practice astrology
The magi, coming from (presumably) a nonJewish territory still
practicing astrology, may have blended Jewish teachings with
astrology. More over, there was no monolithic 'astrology' at that
time, but a variety of practices, each with its own lore and methods
Alignments of planets would have been closely, if not accurately,
predictable at that time. Almanacs were good enough from Babylonian
and Greek astronomy. The magi were not seeing, among the planets,
unknowable or unpredictable events. They may have studied the planets
to improve their almanacs or to satisfy themselfs that the almanacs
were working.
The date of the Nativity is STILL very much unsettled. There are
two schools, the 'early birth' and 'late birth'. The former sets the
Nativity in 6BC (+/- 1 year). The latter puts it in 2BC (+/- 1 year).
The cause is the dispute over when Herodus died.
Matthew says the Nativity occurred during Herodus's reign, which
ended in EITHER 4BC or 1NC. The dispute is about which of two lunar
eclipses immediately preceded his death.
The present AD count of year wasn't started until about 540AD, by
which time memory and records may have been lost. This period was the
initial throes of the Dark Ages, following the collapse of the Roman
empire in the west. It was also the beginning of the Byzantine era in
the east.
As careful as the counting was done, errors easily could have
slipped in. There was provision for a zero year and, in fact, there was
no notion to extend the count before the Nativity.
It REALLY helps to know Latin, to understand documents, coins,
monuments, and the like in reading up on the Star of Bethlehem.