L. l, 1 Carinae
-------------
John Pazmino
NYSkies
nyskiesastronomy@earthlink.net
2006 March 8
Introducction
-----------
On 28 February 2006 European Southern Observatory showed newly
discovered shells or envelopes around three delta Cephei stars. They
were detected by infrared interferometry at delta Cephei itself, alpha
Ursae Minoris (Polaris), and 'L Carinae'. The astronomy and space news
media copied over thiese designations without comment.
I caught immediately that there is no such star 'L Carinaw'.
Perhaps this was a short form of some other name? Reading the many
accounts of the discovery turned up no explanation.
Bayer designations
----------------
In 1603 Johannes Bayerus issued his new scheme for naming stars
using small Greek letters. In general he ordered the stars by their
apparent brightness and applied the letters seriatim until he ran out.
There are 24 letters in the Greek alphabet.
To stretch the supply he multiplexed certain letters by adding a
suffix number. Look at the pi stars of Orion or the tau stars of
Eridanus or the psi stars of Auriga.
Even with multiplexing, many constellations had too many stars
(recall that he observed with eye alone, the telescope being a few
years in the future) for the Greek alphabet.
He continued his naming with small Latin letters. When these ran
out, he dipped into big Latin letters. Within these sequences he
multiplexed, as shown below for L1 and L2 Puppis. These letter sets
satisfied his needs. No constellation went beyond letter 'Q'.
The use of Latin letters is a little known feature of the Bayer
system, often missed by home -- and campus! -- astronomers.
Ex uno, plures
------------
One of the charter constellations handed to us from the Graeco-
Roman era was Argo. This in mytholofy is the ship that roved the sea
in hunt for the Golden Fleece. It was a large sprawling region
embedded in the southern Milky Way with lots of stars discernible to
the eye.
Bayer dutiflly lettered these stars, applying a single sequence of
small Greek, small Latin, and big Latin letters. The farthest letter
he needed was, ta-TAH!, 'Q'.
When in 1930 the International Astronomical Union formalized the
constellation frontiers, it broke up Argo into four smaller groups.
They are the present Carina (keel), Puppis (stern), Pyxis (case for
marine compass), and Vela (sails). Pyxis has only dim stars while the
other three are filled with bright ones.
However, the IAU preserved the original Bayer names from the
former humongous constellation. Hence, for all four new groups there
is ONE SEQUENCE of Bayer letters. There is, for example, an alpha
Carinae, the former alpha Argus, but no 'alpha Velorum'. There is a
delta Velorum, former delta Argus, but no 'delta Puppis'. There is a Q
Puppis, former Q Argus, but no 'Q Carinae'.
Note the nominative and genitives of the constellations; they are
a bit unusual. They are glatt Latin words, so if you have tuition in
that tongue, their orthographical shift does make sense.
+----------------------------------------------------------------+
| NAMES OF ARGO AND ITS DERIVATIVE CONSTELLATIONS |
+------------+------+--------+------------+----------------------+
| nominative | numb | declen | gentitive | Pronunciation |
+------------+------+--------+------------+----------------------+
| Argo | sing | fourth | Argus | ARR-goh, -goos |
| Carina | sing | first | Carinae | ka-REE-na, -nigh |
| Puppis | sing | third | Puppis | PUH-piss, -piss |
| Pyxis | sing | third | Pyxidis | PIKK-siss, -sih-diss |
| Vela | plur | second | Velorum | VEH-la, veh -LOH-rumm |
+------------+------+--------+------------+----------------------+
'Declen' is 'declension', the scheme in Latin for the spelling and
pronunciation for a noun's various grammatical functions. There are
five declensions in Latin, each with its own set of rules.
Flamsteed designations
--------------------
Johannes Flansteed in the early 1700s promulgated a new naming
scheme using only Arabic numbers. From west to east in a constellation
he numbered the stars from '1' to however many he needed. He couldn't
run out of numbers, and some constellations do have well over 100
Flamsteed stars. In Argus, still the one group back then, he numbered
only the stars he could observe from England's latitude. These
happened to be in today's northern Puppis.
With the diffraction of Argo, there was nothing special to do with
the Flamsteed numbers except note that the star such-&-such Argus is
now such-&-such Puppis. I think the last Flamsteed star is 22 Argus,
now 22 Puppis.
The L star
--------
In Argo there was a Bayer star L Argus. This is now L Puppis. The
reason I caught the naming conflict on the spot is that this L Puppis
is a well known variable star. Actually, the star is a close line-of-
sight pair. Bayer named them L1 and L2. L2 is the variable. So vera
mente there is no star called just 'L Puppis' but it is a short way of
saying L2 Puppis.
Because of the one suite of Bayer letters thruout the former Argo
region, there can be no star 'L Carinae'. That would duplicate the one
in Puppis and is historicly impossible.
l and 1
-----
In many type styles these two characters are very similar and in a
quick reading can be confused. Do you remember the 'typewriter'? This
was a large heavy mechanical machine for stamping characters on paper
by pressing the appropriate keys on a console. There generally was NO
KEY FOR THE NUMERAL '1'! You keyed in the letter 'l' for the numeral
'1', so similar they would be if they had separate keys!!
It wasn't until the IBM electric typewriter that 'l' and '1' were
given their own keys. That was a result of the typewriter's potential
to be driven by signals from a computer, where 'l' and '1' had
distinct digital codes.
The l star
--------
Is that 'l' or '1'? For the Cepheid envelope case, the star name
has the small Latin letter 'l', not the Arabic numeral '1'. How to
make sure the reader knows which character is intended?
Easy! Make the 'l' a big letter 'L'. There's no way that looks
like a '1', does it? And so, in all likelihood, the authors merely
wanted to avoid mixing up the two characters and wrote the star name
with a big 'L'.
Also in all likelihood they didn't realize they were accidently
duplicating the name of a whole other star -- also a variable of
substantial interest! -- in Puppis. They also probably never thought
there was a 1 Puppis out there.
1 L of an l
---------
Thus now we have a charming example of how some fellows two and
more thousand years ago who defined the constellations and two
European chaps in the 1600s and 1700s who marked letters and numbers
on the stars come to bedevil us in this 21st century.
Here are some specs for the three stars in this tangle of names
+----------------------------------------------------------------+
| THE L, l, AND 1 STARS OF ARGO AND ITS DERIVATIVES |
+-----------+--------+---------+------+----+------+------+-------+
| Star name | Rt Asc | Declin | Magn | Sp | LY | HR # | HIP # |
+-----------+--------+---------+------+----+------+------+-------+
| l Carinae | 09h45m | -62d31m | 3.7v | G5 | 1510 | 3884 | 47854 |
| L Puppis | 07h14m | -44d28m | 4.4v | M5 | 198 | 2748 | 34922 |
| 1 Puppis | 07h44m | -28d24m | 4.6 | K5 | 977 | 2993 | 32648 |
+-----------+--------+---------+------+----+------+------+-------+
The distances to the stars remain uncertain. You may find other values
elsewhere.
+-----------+---------+-------+---------+----------+
| Star name | Max-min | Days | Type | Comments |
+-----------+---------+-------+---------+----------+
| l Carinae | 3.3-4.2 | 35.53 | del Cep | = ZZ Car |
| L Puppis | 2.6-6.2 | ~140 | semireg | = L2 Pup |
| 1 Puppis | 4.6 | suspected unconfirmed var |
+-----------+---------+-------+---------+----------+
Naming variable stars
-------------------
The Bayer system of using as a third tier the big Latin letters
has an important consequence today, even if you haven't heard of this
part of his method. Variable stars are lettered within each
constellation starting with 'R', like R Andromedae, R Cancri, R
Hydrae.
Usually this first letter is said to denote the first variable
found in a constellation. Not quite; it's the first variable to
receive its own designation. If a newly found variable already has a
Bayer Greek letter OR A BAYER BIG LATIN LETTER, it keeps that letter
and is NOT given a variable star designation. We have beta Persei
(Algol), alpha Orionis (Betelgeuse), and omicron Ceti (Mira).
Lacking of a Greek letter or big Latin letter, we assign it a big
Latin letter starting with R. Why R? Recall from above that the last
such letter used by Bayer was Q. It was felt that as long as this
system was already in place, it was merely extended to fill out the
alphabet for variable stars.
For constellations that didn't make it thru Q, the intervening
letters are forfeited. There could be a constellation with regular
stars thru M, then variable stars R and out. N thru Q are lost.
In the 19th century when variable stars were first treated
seriously, we believed they were rare items. How many could there
possibly be in a constellation? The letters R thru Z would surely
cover all that may be found.
Wrong.
More letters
----------
When the number of variables in a constellation exceded the
alphabet thru Z, a double-letter designation was invented. I don't go
thru the details here but the first letter must be less than or equal
to the second. We have, as examples, CY Aquarii, SS Cygni, BL
Lacertae, and, yep, RS Ophiuchi.
L2 Puppis when realized to be a variable star already had the L3
name. We left it alone without giving it a new variable star letter. l
(small Latin letter) Carinae, on the other hand, when enrolled among
the variable stars, was given the next available letter combo, This
happened to be ZZ; we got a ZZ Carinae.
After exhausting the possible double-letters, we gave up and went
to numbers, like V361 Orionis and V838 Monocerotis.
It would be far better if the discovery authors used the variable
star name ZZ Carinae in the stead of the mistaken 'L Carinae'.