Sky and Telescope - February 2018 - 49

+36°

M38
1907

AE

Y 698
q
18

19
IC 410
1893

IC 405
AR

+34°

16
14

UV

+32°

Star magnitudes

is implied in AE Aur's designation.
ming in alphabet soup, you know you're
FOLLOW THE SHOWER ONLINE: As meteor observers report their
You've probably ﬁgured out that variable surrounded by shifting magnitudes.
counts to the IMO, you can watch this year's Perseid activity curve
stars
comprise
confused
alphabet,
AE Aur is worth a look for its vari.
develop
hour bya hour
at imo.net
with seemingly random letters assigned
ability, but what makes it really shine
to them;
R was
Andromedae,
Tauri,
for me is its dramatic past: It's a "runThe
1980 think
display
one of theTbest
watch
this,
as it should
happen
ZZmemory
Cygni. But
there's
logic to
these
away," for
a star
tossed
out of its
home duras
in
up to
then;a many
observers
ing
hours when
the
letters. Ifseeing
a newly
discovered
variable
the their
resultearly-morning
of a binary collision
or ejecreported
more
than 120
per hour
Perseid
radiant
highest.
has aoccasionally
Bayer designation
letter,
tion. About
15%isof
O- and B-type stars
and
up to 5(a
orGreek
6 a minute.
meteor
like
Alpha orJapanese
Beta), that
designation
areMoreover,
runaways,French
so they're
not expert
extremely
A
reputable
observer
counted
Jérémie
calculated
an
butVaubaillon
there's stillhas
something
intrigunearly
250Ifin
one hour.
remains.
it doesn't
have a Bayer desig- rare,
older
discrete
trail
of the
ing
about
a star
living
farcomet's
from itsrubble
The Perseid
nation,
it gets ameteoroids
letter fromare
thedusty
Roman
dating backAE
to Aur
1079.
forecasts
Earth
birthplace.
is He
thought
to have
debris
bitsbeginning
shed by the
periodic
comet
alphabet,
with
R, assigned
passing closest
to thenear
middle
this
originated
in Orion,
theof
current
109P/Swift-Tuttle,
which
discovered
to it. This is how we
got Rwas
Persei,
for
trail at 4:56
UT Trapezium
February 12th,
which
of the
cluster.
About
in
the summer
of 1862.
Many
experts in location
example.
The next
variable
discovered
would
favor
eastern
on
2
million
years
ago, aNorth
close America
interaction
in
the 19th andwithout
20th centuries
a constellation
a Bayer caldesignatop of whatever
else is happening.
This
between
two high-mass
binary systems
culated
its orbital
period
to be T.
120
±2
tion becomes
S, and
the third
If nine
might lead two
to a of
sudden
, buttoVaubaillon
compelled
the stars
"trade
years,
and
summer
1981 constellation
was considered
variable
stars
in a single
cautions,
"This 1079
[is] quite
places"
(leaving
theirtrail
original
com- old,
the
"most probable"
timethe
forletters
the comet
are discovered,
running
from
making the
forecasting
less
certain. I
panions)
and
form a new
double-star
to
be recovered.
Meteoroids
tend
to be
R through
to Z, the
10th star
name
certainlyIota
would
look for it,
justtwo
keep
system,
(ι) Orionis.
Thebut
other
thicker
in the
vicinity
of up
their
jumps back
and
doubles
on parR: RR,
in mind
the uncertainties."
stars
became
runaways, ejected from
ent
RS, comet,
RT, andso
soastronomers
on, down to naturally
RZ. Then we
their systems at velocities as high as
assumed
move on that
to SS,the
ST,strong
etc. Perseid activity
1000
s-1has
in 1980
was due
to the system
impending
But there's
another
for
■ JOEkm
RAO
beenmotion
an assiduous
ama. Proper
measurearrival
Swift-Tuttle.
variableofstar
names as well. Only 334
teur astronomer
for nearly
50and
years.
ments
have revealed
AE Aur
MuHe
(μ)
If thisRhappens
about everyexist,
12 years
possible
to Z combinations
so if
won
the Astronomical
Columbae
to be these League's
lost suns.Walter
in
sync with Jupiter's
orbital
we
a constellation
contains
moreperiod,
variables
Scott
Award
2009.
AE Houston
Aur lights
up ICin405,
the Flaming
have
nicethe
explanation
for not
only
than athat,
335th becomes
V335
Contact
Joe:but
Star Nebula,
its
relationship
jrao@gmail.com with
the
strong
1980 display,
but
also ﬁthe
(V for
Variable).
However,
you'll
nd
this gaseous dust cloud is coincidental;
enhanced
were or
reported
in AE's just passing through. Recently,
V-numbersshowers
printedthat
together,
entirely
2004,
1968, 1945,
and 1921.
supplanting,
R-numbers
on some
astronomers analyzed AE's spectrum to
charts. R Andromedae may be listed as
reveal, for the ﬁrst time, X-ray emission
R
And,
or
it
may
be
denoted
as
V1.
Or
from a stellar bow shock (the shock
What About 2016?
both.
It's
not
always
possible
to
tell
if
wave produced by a star's rapid moveThis would appear to be another of those
a star isyears."
variable
from its
nameexpert
("Beta
ment through the interstellar medium).
"prime
Russian
meteor
Persei" doesn't
giveclosely
away the
Prior to this discovery, bow shocks for
Mikhail
Maslov,really
who has
studied
game),
but if you
ﬁnd
yourself
swimrunaways had been detected only in the
the
evolution
of the
Perseid
stream
in
space, predicts a "signiﬁcant increase
of Perseid background activity, with a
zenithal hourly rate (ZHR) of 150-160."
By comparison, last year's Perseid shower
reached a peak ZHR of about 90, judging
from the counts submitted to the Interevening of February 28th, with Regulus
national
Meteor
(IMO) by
THE BEST
VIEW Organization
of the lunar occultajust meeting the edge of the not-quiteobservers
worldwide.
tion of Regulus
on February 1st is from
full Moon. Quebec and eastern Canada
The shower's
time
of maxinorthern
Europepredicted
and Asia.
Much
better
watch after midnight, in the earliest
mum
is continent
12:40 UT February
12th.
for our
is the event
onThat's
the
after
for North
America,
but peak
nightsunrise
of February
28-March
1, when
the hours of Thursday, March 1st.
Some timings: Anchorage, disappearactivity
usuallythe
lasts
about 24 hours.
Moon occults
1st-magnitude
star
ance 7:39 p.m., graze 7:49 p.m., reappearpoints
outAmerica,
that in addition,
forMaslov
northern
North
including
ance 8:05 p.m. AKST; Yellowknife, d.
fresh
trails
shed
by Swift-Tuttle
muchdebris
of Maine
and
eastern
Canada.
in
1479onand
("fresh"
dense 9:57 p.m., r. 10:36 p.m. MST; Quebec
Those
the1862
southern
edgeimplies
of the occulCity, d. 1:05 a.m., gr. 1:20 a.m., r. 1:29
and
narrow)
willsee
likely
encounter
tation
path will
a grazing
event,Earth
a.m. EST; Bangor, d. 1:15 a.m., gr. 1:25
and
also
provideina and
briefout
enhancewithmight
Regulus
winking
as the
a.m., r. 1:32 a.m. EST; Halifax, d. 2:12
ment
activity.
and
lunar of
limb
passesEastern
in frontEurope
of the star.
a.m., gr. 2:25 a.m., r. 2:45 a.m. AST.
western
Asiathe
areoccultation
in the bestearly
position
to
Alaska sees
on the

AURIGA

2
3
4
5
6
7
8

+30°

`
5h 30m

5h 25m

5h 20m

5h 15m

+28°

p A double line of stars southwest of M38
helps point the way to the variable AE Aurigae.

radio and mid-infrared.
As it turns out, AE is itself a multiple-star system. It claims one close
8th-magnitude companion, B, and one
distant 10th-magnitude companion, C
(HD 34042). So at least it's had company on its long trip away from home.

CREDIT X X X X X X X X X X X X X X X

Lunar Occultations

The occultation of Aldebaran on
February 23rd is best for Europe and
northern Russia. Northeast North
America and the Atlantic see a daylight
occultation, but the Moon won't be too
high. For Bermuda, the Moon stands
only 7° high at the time of disappearance. Halifax is a bit better: The Moon
is 10° high at disappearance, 20° high
at reappearance. Some timings: Hamilton, Bermuda, disappearance 12:32
p.m. AST; Halifax, NS, d. 11:57 a.m.
AST, reappearance 12:48 p.m. AST.
sk yandtelescope.com * FE B RUA RY 2 018

49
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