Sky & Telescope - April 2023 - 40
HUBBLE HERITAGE TEAM (AURA / STSCI / NASA)
Novae
magnitude +1.3; and finally Nova Puppis 1942, climbing to
magnitude +0.5.
And the 80-plus years since? Nothing at all: The brightest
blast was second-magnitude Nova Cygni 1975. " That's a scandal, "
says Bradley Schaefer (Louisiana State University). He
thinks those bright novae are still appearing in our sky. " No
one spots them! It's horrifying. "
Schaefer blames a shift in observing habits. Starting
around 1890, talented amateur astronomers made a sport of
finding novae. These observers memorized the naked-eye stars
and searched the sky for new ones. After World War II, warsurplus
binoculars flooded the country, giving amateurs the
chance to find fainter and farther novae. But because distant
novae congregate in the band of the Milky Way, that's where
amateurs conducted their searches. As a result, he says, the
brightest and nearest novae, outside that band, were missed.
Increasing light pollution has only exacerbated the problem
by masking novae as they brighten and fade.
But Shafter is skeptical of this claim, saying the disparIN
A CROWD Novae have even erupted in star clusters - specifically
in globular clusters, which are some of the most ancient denizens of our
galaxy. (Most open clusters are too young for novae.) In 1860 observers
saw a nova in M80 (above), a globular cluster in Scorpius. A second
nova, in 1938, appeared in M14 in Ophiuchus, but astronomers spotted
that blast only decades later by examining old photographic plates.
assumed in the 1970s when predicting that novae contribute
significant amounts of lithium to the galaxy. In contrast,
supernovae occur in the Milky Way perhaps twice a century.
So nova explosions happen 1,000 to 2,000 times more often
than supernovae.
Where Have All the Bright Novae Gone?
However, a specter haunts these calculations: Bright novae
seem to have vanished.
During the first half of the 20th century, a nova peaked
at first magnitude or brighter each decade. The first, Nova
Persei 1901, hit magnitude +0.2 and rivaled Rigel in brightness.
Next came the brightest nova ever known, Nova Aquilae
1918, which attained magnitude -1.1 and almost surpassed
Sirius. The following decades featured Nova Pictoris 1925,
reaching magnitude +1.0; Nova Herculis 1934, peaking at
ity is " probably just due to small-number statistics. " In 2017
he calculated that the difference between the earlier era and
the modern one has a 10% chance of being a statistical fluke.
That's about the same chance you can flip a fair coin and get
heads three times in a row. Most scientists consider such a
significance level suggestive but not definitive.
Schaefer calculates the odds differently: " It's significant
past the 3-sigma level, " which means a 0.3% significance level
- equivalent to getting eight or nine heads in a row. " That's
not a fluke. " He says modern observers fail to find about half
of the brightest novae.
But Starrfield can't believe amateur astronomers would
miss novae as bright as first or second magnitude. " These
guys really know the sky, " he says. " I don't know the sky at
all; I mean, I'm lucky to find Jupiter. "
Whatever the case, someday - or, more precisely, some
night - the next bright nova will shine. Why not be the one
who finds it? Scanning the whole sky with the naked eye
before peering through a scope might yield that long-overdue
bright nova - and you'll make astronomical history.
¢ KEN CROSWELL has neither a cell phone nor a car, but he
does like nucleosynthesis.
All Known Novae of First Magnitude and Brighter from 1900 to 2022
Name
Nova Persei 1901
Nova Aquilae 1918
Nova Pictoris 1925
Nova Herculis 1934
Nova Puppis 1942
40 APRIL 2023 * SKY & TELESCOPE
Variable-Star Name
GK Persei
V603 Aquilae
RR Pictoris
DQ Herculis
CP Puppis
Brightest Apparent Mag(v)
+0.2
−1.1
+1.0
+1.3
+0.5
Distance (ly)
1,420
1,060
1,630
1,620
2,550
Orbital Period (d)
2.0
0.14
0.15
0.19
0.06
Sky & Telescope - April 2023
Table of Contents for the Digital Edition of Sky & Telescope - April 2023
Contents
Sky & Telescope - April 2023 - Cover1
Sky & Telescope - April 2023 - Cover2
Sky & Telescope - April 2023 - 1
Sky & Telescope - April 2023 - Contents
Sky & Telescope - April 2023 - 3
Sky & Telescope - April 2023 - 4
Sky & Telescope - April 2023 - 5
Sky & Telescope - April 2023 - 6
Sky & Telescope - April 2023 - 7
Sky & Telescope - April 2023 - 8
Sky & Telescope - April 2023 - 9
Sky & Telescope - April 2023 - 10
Sky & Telescope - April 2023 - 11
Sky & Telescope - April 2023 - 12
Sky & Telescope - April 2023 - 13
Sky & Telescope - April 2023 - 14
Sky & Telescope - April 2023 - 15
Sky & Telescope - April 2023 - 16
Sky & Telescope - April 2023 - 17
Sky & Telescope - April 2023 - 18
Sky & Telescope - April 2023 - 19
Sky & Telescope - April 2023 - 20
Sky & Telescope - April 2023 - 21
Sky & Telescope - April 2023 - 22
Sky & Telescope - April 2023 - 23
Sky & Telescope - April 2023 - 24
Sky & Telescope - April 2023 - 25
Sky & Telescope - April 2023 - 26
Sky & Telescope - April 2023 - 27
Sky & Telescope - April 2023 - 28
Sky & Telescope - April 2023 - 29
Sky & Telescope - April 2023 - 30
Sky & Telescope - April 2023 - 31
Sky & Telescope - April 2023 - 32
Sky & Telescope - April 2023 - 33
Sky & Telescope - April 2023 - 34
Sky & Telescope - April 2023 - 35
Sky & Telescope - April 2023 - 36
Sky & Telescope - April 2023 - 37
Sky & Telescope - April 2023 - 38
Sky & Telescope - April 2023 - 39
Sky & Telescope - April 2023 - 40
Sky & Telescope - April 2023 - 41
Sky & Telescope - April 2023 - 42
Sky & Telescope - April 2023 - 43
Sky & Telescope - April 2023 - 44
Sky & Telescope - April 2023 - 45
Sky & Telescope - April 2023 - 46
Sky & Telescope - April 2023 - 47
Sky & Telescope - April 2023 - 48
Sky & Telescope - April 2023 - 49
Sky & Telescope - April 2023 - 50
Sky & Telescope - April 2023 - 51
Sky & Telescope - April 2023 - 52
Sky & Telescope - April 2023 - 53
Sky & Telescope - April 2023 - 54
Sky & Telescope - April 2023 - 55
Sky & Telescope - April 2023 - 56
Sky & Telescope - April 2023 - 57
Sky & Telescope - April 2023 - 58
Sky & Telescope - April 2023 - 59
Sky & Telescope - April 2023 - 60
Sky & Telescope - April 2023 - 61
Sky & Telescope - April 2023 - 62
Sky & Telescope - April 2023 - 63
Sky & Telescope - April 2023 - 64
Sky & Telescope - April 2023 - 65
Sky & Telescope - April 2023 - 66
Sky & Telescope - April 2023 - 67
Sky & Telescope - April 2023 - 68
Sky & Telescope - April 2023 - 69
Sky & Telescope - April 2023 - 70
Sky & Telescope - April 2023 - 71
Sky & Telescope - April 2023 - 72
Sky & Telescope - April 2023 - 73
Sky & Telescope - April 2023 - 74
Sky & Telescope - April 2023 - 75
Sky & Telescope - April 2023 - 76
Sky & Telescope - April 2023 - 77
Sky & Telescope - April 2023 - 78
Sky & Telescope - April 2023 - 79
Sky & Telescope - April 2023 - 80
Sky & Telescope - April 2023 - 81
Sky & Telescope - April 2023 - 82
Sky & Telescope - April 2023 - 83
Sky & Telescope - April 2023 - 84
Sky & Telescope - April 2023 - Cover3
Sky & Telescope - April 2023 - Cover4
https://www.nxtbook.com/nxtbooks/aas/st_202501
https://www.nxtbook.com/nxtbooks/aas/st_202412
https://www.nxtbook.com/nxtbooks/aas/st_202411
https://www.nxtbook.com/nxtbooks/aas/st_202410
https://www.nxtbook.com/nxtbooks/aas/st_202409
https://www.nxtbook.com/nxtbooks/aas/st_202408
https://www.nxtbook.com/nxtbooks/aas/st_202407
https://www.nxtbook.com/nxtbooks/aas/st_202406
https://www.nxtbook.com/nxtbooks/aas/st_202405
https://www.nxtbook.com/nxtbooks/aas/st_202404_qr
https://www.nxtbook.com/nxtbooks/aas/st_202404
https://www.nxtbook.com/nxtbooks/aas/st_202403
https://www.nxtbook.com/nxtbooks/aas/st_202402
https://www.nxtbook.com/nxtbooks/aas/st_202401_aus
https://www.nxtbook.com/nxtbooks/aas/st_202401
https://www.nxtbook.com/nxtbooks/aas/st_202312_aus
https://www.nxtbook.com/nxtbooks/aas/st_202312
https://www.nxtbook.com/nxtbooks/aas/st_202311
https://www.nxtbook.com/nxtbooks/aas/st_202310
https://www.nxtbook.com/nxtbooks/aas/st_202309
https://www.nxtbook.com/nxtbooks/aas/st_202308
https://www.nxtbook.com/nxtbooks/aas/st_202307
https://www.nxtbook.com/nxtbooks/aas/st_202306
https://www.nxtbook.com/nxtbooks/aas/st_202305
https://www.nxtbook.com/nxtbooks/aas/st_202304
https://www.nxtbook.com/nxtbooks/aas/st_202304_qr
https://www.nxtbook.com/nxtbooks/aas/st_202303
https://www.nxtbook.com/nxtbooks/aas/st_202302
https://www.nxtbook.com/nxtbooks/aas/st_202301
https://www.nxtbook.com/nxtbooks/aas/st_202212
https://www.nxtbook.com/nxtbooks/aas/st_202211
https://www.nxtbook.com/nxtbooks/aas/st_202210
https://www.nxtbook.com/nxtbooks/aas/st_202209
https://www.nxtbook.com/nxtbooks/aas/st_202208
https://www.nxtbook.com/nxtbooks/aas/st_202207
https://www.nxtbook.com/nxtbooks/aas/st_202206
https://www.nxtbook.com/nxtbooks/aas/st_202205
https://www.nxtbook.com/nxtbooks/aas/st_202204
https://www.nxtbook.com/nxtbooks/aas/st_202203
https://www.nxtbook.com/nxtbooks/aas/st_202202
https://www.nxtbook.com/nxtbooks/aas/st_202201
https://www.nxtbook.com/nxtbooks/aas/st_202112
https://www.nxtbook.com/nxtbooks/aas/st_202111
https://www.nxtbook.com/nxtbooks/aas/st_202110
https://www.nxtbook.com/nxtbooks/aas/st_202109
https://www.nxtbook.com/nxtbooks/aas/st_202108
https://www.nxtbook.com/nxtbooks/aas/st_202107
https://www.nxtbook.com/nxtbooks/aas/st_202106
https://www.nxtbook.com/nxtbooks/aas/st_202105
https://www.nxtbook.com/nxtbooks/aas/st_202104
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/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