Sky & Telescope - January 2021 - 45

Evenings with the Stars by Fred Schaaf

Orion's
Magnificent
Seven
Winter's best-known
constellation is also its
brightest.

A K IR A FUJII

I

experienced my first evenings with the
stars - that is, real outings of marveling and learning - in the winter in
which I turned six years old. The first
constellation I discovered that winter is
still my favorite. It's also the one that
almost everyone considers finest of all:
Orion the Hunter.
The brightest constellation. There
are only two constellations other than
Orion that contain two stars of 1stmagnitude or brighter. These are the farsouth groupings Centaurus (the Centaur) and Crux (the Southern Cross).
But neither of these has the visual
appeal of Orion. Crux is very small, and
its cross shape lacks the crucial middle
star. The main pattern of Centaurus
contains many rather bright stars but is
large and sprawling. In contrast, Orion's
seven principal stars include +0.2-magnitude Rigel, +0.4-magnitude (usually)
Betelgeuse, and five stars of roughly 2nd
magnitude: Bellatrix, Alnitak, Alnilam,
Mintaka, and Saiph. Together, they
make Orion the most concentratedly
brilliant constellation of all.
Compare Orion's seven stars to the
same number making up the Big Dipper. This extremely famous asterism (an
unofficial pattern of stars) contains
no suns of 1st magnitude or brighter, a
half-dozen 2nd-magnitude lights, and
a single 3rd-magnitude star. Of course,
the Big Dipper catches our attention
because it so closely resembles such a
well-known implement, a pan or ladle.
But Orion represents the most familiar
and interesting of all shapes to us: the
human body.

WINTER LIGHTS Orion the Hunter stands out even amongst the many bright stars of the
winter sky. The constellation's distinctive three-in-a-row Belt, along with Betelgeuse and
Rigel, make it easy to identify.

Contrasting Betelgeuse and Rigel.
No other constellation's brightest two
stars provide so strong a color contrast
as blue-white Rigel and orange-yellow
Betelgeuse. Most people can notice the
difference in these hues by glancing
back and forth between the stars with
the naked eye.
This month also provides the
unusual opportunity to compare the
colors of Betelgeuse and Mars. As our
star chart (on pages 42-43) shows,
both objects are visible together during
evening hours. What's more, the Red
Planet is currently in the same brightness range as Betelgeuse.
I've called both the star and the
planet "campfire-colored." Robert
Burnham, Jr., in his classic Burnham's
Celestial Handbook, used a different
descriptor. He wrote, "The exotic word
padparadscha, used in India to designate
the rare orange sapphire, might be an
appropriate name for Betelgeuse."
The only first-magnitude star that
varies greatly in brightness. Amazingly, last winter Betelgeuse unexpectedly dimmed so much that some

observers estimated it to be as faint as
magnitude 1.8. That's very slightly dimmer than the Hunter's other shoulderstar, Bellatrix, and two of the stars in
his Belt. But historically Betelgeuse may
also have been uncharacteristically
bright at times. The great astronomer
John Herschel wrote in December 1852
that Betelgeuse was then "the largest
star in the northern hemisphere." In
this context, "largest" meant "brightest," suggesting a magnitude of -0.1 or
better - equalling golden Arcturus in
Boötes. Former Sky & Telescope editor in
chief Joseph Ashbrook also estimated
Betelgeuse to be magnitude -0.1 at its
most luminous during a period spanning 1937 to 1975.
Orion on the meridian. The blazing
stars of Orion are near the meridian
around 9 p.m. at month's end. Remarkably, the second and third brightest
stars of winter (Capella, in Auriga, and
Rigel, respectively) transit the meridian
at almost exactly the same time.
„ FRED SCHAAF welcomes your letters
and comments at fschaaf@aol.com.
sk yandtelescope.org * JANUARY 2 021

45


http://www.skyandtelescope.org

Sky & Telescope - January 2021

Table of Contents for the Digital Edition of Sky & Telescope - January 2021

Contents
Sky & Telescope - January 2021 - Cover1
Sky & Telescope - January 2021 - Cover2
Sky & Telescope - January 2021 - 1
Sky & Telescope - January 2021 - Contents
Sky & Telescope - January 2021 - 3
Sky & Telescope - January 2021 - 4
Sky & Telescope - January 2021 - 5
Sky & Telescope - January 2021 - 6
Sky & Telescope - January 2021 - 7
Sky & Telescope - January 2021 - 8
Sky & Telescope - January 2021 - 9
Sky & Telescope - January 2021 - 10
Sky & Telescope - January 2021 - 11
Sky & Telescope - January 2021 - 12
Sky & Telescope - January 2021 - 13
Sky & Telescope - January 2021 - 14
Sky & Telescope - January 2021 - 15
Sky & Telescope - January 2021 - 16
Sky & Telescope - January 2021 - 17
Sky & Telescope - January 2021 - 18
Sky & Telescope - January 2021 - 19
Sky & Telescope - January 2021 - 20
Sky & Telescope - January 2021 - 21
Sky & Telescope - January 2021 - 22
Sky & Telescope - January 2021 - 23
Sky & Telescope - January 2021 - 24
Sky & Telescope - January 2021 - 25
Sky & Telescope - January 2021 - 26
Sky & Telescope - January 2021 - 27
Sky & Telescope - January 2021 - 28
Sky & Telescope - January 2021 - 29
Sky & Telescope - January 2021 - 30
Sky & Telescope - January 2021 - 31
Sky & Telescope - January 2021 - 32
Sky & Telescope - January 2021 - 33
Sky & Telescope - January 2021 - 34
Sky & Telescope - January 2021 - 35
Sky & Telescope - January 2021 - 36
Sky & Telescope - January 2021 - 37
Sky & Telescope - January 2021 - 38
Sky & Telescope - January 2021 - 39
Sky & Telescope - January 2021 - 40
Sky & Telescope - January 2021 - 41
Sky & Telescope - January 2021 - 42
Sky & Telescope - January 2021 - 43
Sky & Telescope - January 2021 - 44
Sky & Telescope - January 2021 - 45
Sky & Telescope - January 2021 - 46
Sky & Telescope - January 2021 - 47
Sky & Telescope - January 2021 - 48
Sky & Telescope - January 2021 - 49
Sky & Telescope - January 2021 - 50
Sky & Telescope - January 2021 - 51
Sky & Telescope - January 2021 - 52
Sky & Telescope - January 2021 - 53
Sky & Telescope - January 2021 - 54
Sky & Telescope - January 2021 - 55
Sky & Telescope - January 2021 - 56
Sky & Telescope - January 2021 - 57
Sky & Telescope - January 2021 - 58
Sky & Telescope - January 2021 - 59
Sky & Telescope - January 2021 - 60
Sky & Telescope - January 2021 - 61
Sky & Telescope - January 2021 - 62
Sky & Telescope - January 2021 - 63
Sky & Telescope - January 2021 - 64
Sky & Telescope - January 2021 - 65
Sky & Telescope - January 2021 - 66
Sky & Telescope - January 2021 - 67
Sky & Telescope - January 2021 - 68
Sky & Telescope - January 2021 - 69
Sky & Telescope - January 2021 - 70
Sky & Telescope - January 2021 - 71
Sky & Telescope - January 2021 - 72
Sky & Telescope - January 2021 - 73
Sky & Telescope - January 2021 - 74
Sky & Telescope - January 2021 - 75
Sky & Telescope - January 2021 - 76
Sky & Telescope - January 2021 - 77
Sky & Telescope - January 2021 - 78
Sky & Telescope - January 2021 - 79
Sky & Telescope - January 2021 - 80
Sky & Telescope - January 2021 - 81
Sky & Telescope - January 2021 - 82
Sky & Telescope - January 2021 - 83
Sky & Telescope - January 2021 - 84
Sky & Telescope - January 2021 - Cover3
Sky & Telescope - January 2021 - Cover4
Sky & Telescope - January 2021 - SA1
Sky & Telescope - January 2021 - SA2
Sky & Telescope - January 2021 - SA3
Sky & Telescope - January 2021 - SA4
Sky & Telescope - January 2021 - SA5
Sky & Telescope - January 2021 - SA6
Sky & Telescope - January 2021 - SA7
Sky & Telescope - January 2021 - SA8
Sky & Telescope - January 2021 - SA9
https://www.nxtbook.com/nxtbooks/aas/st_202103
https://www.nxtbook.com/nxtbooks/aas/st_202102
https://www.nxtbook.com/nxtbooks/aas/st_202101
https://www.nxtbook.com/nxtbooks/aas/skywatch_2021
https://www.nxtbook.com/nxtbooks/aas/st_202012
https://www.nxtbook.com/nxtbooks/aas/st_202011
https://www.nxtbook.com/nxtbooks/aas/st_202010
https://www.nxtbook.com/nxtbooks/aas/st_202009
https://www.nxtbook.com/nxtbooks/aas/st_202008
https://www.nxtbook.com/nxtbooks/aas/st_202007
https://www.nxtbook.com/nxtbooks/aas/st_202006
https://www.nxtbook.com/nxtbooks/aas/st_202005
https://www.nxtbook.com/nxtbooks/aas/st_202004
https://www.nxtbook.com/nxtbooks/aas/st_202003
https://www.nxtbook.com/nxtbooks/aas/st_202002
https://www.nxtbook.com/nxtbooks/aas/st_202001
https://www.nxtbook.com/nxtbooks/aas/st_201912
https://www.nxtbook.com/nxtbooks/aas/st_201911
https://www.nxtbook.com/nxtbooks/aas/st_201910
https://www.nxtbook.com/nxtbooks/aas/st_201909
https://www.nxtbook.com/nxtbooks/aas/st_201908
https://www.nxtbook.com/nxtbooks/aas/st_201907
https://www.nxtbook.com/nxtbooks/aas/st_201906
https://www.nxtbook.com/nxtbooks/aas/st_201905
https://www.nxtbook.com/nxtbooks/aas/st_201904
https://www.nxtbook.com/nxtbooks/aas/st_201903
https://www.nxtbook.com/nxtbooks/aas/st_201902
https://www.nxtbook.com/nxtbooks/aas/st_201901
https://www.nxtbook.com/nxtbooks/aas/st_201812
https://www.nxtbook.com/nxtbooks/aas/st_201811
https://www.nxtbook.com/nxtbooks/aas/st_201810
https://www.nxtbook.com/nxtbooks/aas/st_201809
https://www.nxtbook.com/nxtbooks/aas/st_201808
https://www.nxtbook.com/nxtbooks/aas/st_201807
https://www.nxtbook.com/nxtbooks/aas/st_201806
https://www.nxtbook.com/nxtbooks/aas/st_201805
https://www.nxtbook.com/nxtbooks/aas/st_201804
https://www.nxtbook.com/nxtbooks/aas/st_201803
https://www.nxtbook.com/nxtbooks/aas/st_201802
https://www.nxtbook.com/nxtbooks/aas/st_201801
https://www.nxtbook.com/nxtbooks/aas/st_201712
https://www.nxtbook.com/nxtbooks/aas/st_201711
https://www.nxtbook.com/nxtbooks/aas/st_201710
https://www.nxtbook.com/nxtbooks/aas/st_201709
https://www.nxtbook.com/nxtbooks/aas/st_201708
https://www.nxtbook.com/nxtbooks/aas/st_201707
https://www.nxtbook.com/nxtbooks/aas/st_201706
https://www.nxtbook.com/nxtbooks/aas/st_201705
https://www.nxtbook.com/nxtbooks/aas/st_201704
https://www.nxtbook.com/nxtbooks/aas/st_201703
https://www.nxtbook.com/nxtbooks/aas/st_201702
https://www.nxtbook.com/nxtbooks/aas/st_201701
https://www.nxtbook.com/nxtbooks/aas/st_201612
https://www.nxtbook.com/nxtbooks/aas/st_201611
https://www.nxtbook.com/nxtbooks/newtrack/st_201612
https://www.nxtbook.com/nxtbooks/aas/st_201610
https://www.nxtbook.com/nxtbooks/aas/st_201609
https://www.nxtbook.com/nxtbooks/aas/st_201608
https://www.nxtbook.com/nxtbooks/aas/st_201607
https://www.nxtbook.com/nxtbooks/aas/st_201606
https://www.nxtbook.com/nxtbooks/aas/st_201605
https://www.nxtbook.com/nxtbooks/aas/st_201604
https://www.nxtbook.com/nxtbooks/aas/st_201603
https://www.nxtbook.com/nxtbooks/aas/st_201602
https://www.nxtbook.com/nxtbooks/aas/st_201601
https://www.nxtbook.com/nxtbooks/aas/st_201512
https://www.nxtbook.com/nxtbooks/aas/st_201511
https://www.nxtbook.com/nxtbooks/aas/st_201510
https://www.nxtbook.com/nxtbooks/aas/st_201509
https://www.nxtbook.com/nxtbooks/aas/st_201508
https://www.nxtbook.com/nxtbooks/aas/st_201507
https://www.nxtbook.com/nxtbooks/aas/st_201506
https://www.nxtbook.com/nxtbooks/aas/st_201505
https://www.nxtbook.com/nxtbooks/aas/st_201504
https://www.nxtbook.com/nxtbooks/aas/st_201503
https://www.nxtbook.com/nxtbooks/aas/st_201502
https://www.nxtbook.com/nxtbooks/aas/st_201501
https://www.nxtbook.com/nxtbooks/aas/st_201412
https://www.nxtbook.com/nxtbooks/aas/st_201411
https://www.nxtbook.com/nxtbooks/aas/st_201410
https://www.nxtbook.com/nxtbooks/aas/st_201409
https://www.nxtbook.com/nxtbooks/aas/st_201408
https://www.nxtbook.com/nxtbooks/aas/st_201407
https://www.nxtbook.com/nxtbooks/aas/st_201406
https://www.nxtbook.com/nxtbooks/aas/st_mars
https://www.nxtbook.com/nxtbooks/aas/st_201405
https://www.nxtbook.com/nxtbooks/aas/st_201404
https://www.nxtbook.com/nxtbooks/aas/st_201403
https://www.nxtbook.com/nxtbooks/aas/st_201402
https://www.nxtbook.com/nxtbooks/aas/st_201401
https://www.nxtbook.com/nxtbooks/aas/st_201312
https://www.nxtbook.com/nxtbooks/aas/st_201311
https://www.nxtbook.com/nxtbooks/aas/st_201310
https://www.nxtbook.com/nxtbooks/aas/st_201309
https://www.nxtbook.com/nxtbooks/aas/st_201308
https://www.nxtbook.com/nxtbooks/aas/st_201307
https://www.nxtbook.com/nxtbooks/aas/st_201306
https://www.nxtbook.com/nxtbooks/aas/st_201305
https://www.nxtbook.com/nxtbooks/aas/st_201304
https://www.nxtbook.com/nxtbooks/aas/st_201303
https://www.nxtbook.com/nxtbooks/aas/st_201302
https://www.nxtbook.com/nxtbooks/aas/st_201301
https://www.nxtbook.com/nxtbooks/aas/st_201212
https://www.nxtbook.com/nxtbooks/aas/st_201211
https://www.nxtbook.com/nxtbooks/aas/st_201210
https://www.nxtbook.com/nxtbooks/aas/st_201209
https://www.nxtbook.com/nxtbooks/aas/st_201208
https://www.nxtbook.com/nxtbooks/aas/st_201207
https://www.nxtbook.com/nxtbooks/aas/st_201206
https://www.nxtbook.com/nxtbooks/aas/st_201205
https://www.nxtbook.com/nxtbooks/aas/st_201204
https://www.nxtbook.com/nxtbooks/aas/st_201203
https://www.nxtbook.com/nxtbooks/aas/st_201202
https://www.nxtbook.com/nxtbooks/aas/st_201201
https://www.nxtbook.com/nxtbooks/aas/st_201112
https://www.nxtbook.com/nxtbooks/aas/st_201111
https://www.nxtbook.com/nxtbooks/aas/st_201110
https://www.nxtbook.com/nxtbooks/aas/st_201109
https://www.nxtbook.com/nxtbooks/aas/st_201108
https://www.nxtbook.com/nxtbooks/aas/st_201107
https://www.nxtbook.com/nxtbooks/aas/st_201106
https://www.nxtbook.com/nxtbooks/aas/st_201105
https://www.nxtbook.com/nxtbooks/aas/st_201104
https://www.nxtbook.com/nxtbooks/aas/st_201103
https://www.nxtbook.com/nxtbooks/aas/st_201102
https://www.nxtbook.com/nxtbooks/aas/st_201101
https://www.nxtbook.com/nxtbooks/aas/st_201012
https://www.nxtbook.com/nxtbooks/aas/st_201011
https://www.nxtbook.com/nxtbooks/aas/st_201010
https://www.nxtbook.com/nxtbooks/aas/st_201009
https://www.nxtbook.com/nxtbooks/aas/st_201008
https://www.nxtbook.com/nxtbooks/aas/st_201007
https://www.nxtbook.com/nxtbooks/aas/st_201006
https://www.nxtbook.com/nxtbooks/aas/st_201005
https://www.nxtbook.com/nxtbooks/aas/st_201004
https://www.nxtbook.com/nxtbooks/aas/st_201003
https://www.nxtbook.com/nxtbooks/aas/st_201002
https://www.nxtbook.com/nxtbooks/aas/st_201001
https://www.nxtbookmedia.com