Sky & Telescope - January 2025 - 35

ORIGINAL ORC 1 IMAGE: R. NORRIS ET AL. / PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF
AUSTRALIA 2021; THREE INTERPRETATIONS: R. NORRIS ET AL. / MONTHLY NOTICES OF THE ROYAL
ASTRONOMICAL SOCIETY 2022
" Polar " ring
" Equatorial " ring
DISCOVERY The original image of ORC 1 shows a circle spanning
more than 1 arcminute. If the circle is associated with the galaxy at
its center (not shown in this radio image), then it's more than 1 million
light-years across.
" Back " ring
ORCs appear to be the result of gargantuan shock waves
sweeping through intergalactic space.
The question remains, however: What created them?
An Unexpected Journey
ORCs were actually discovered more than once in what Norris
calls " an interesting bit of sociology. "
Anna Kapinska (National Radio Astronomy Observatory)
presented the first odd ring of radio emission at a conference
in late 2019. She showed a black-on-white image, constructed
from radio data, of a thick, fuzzy ring. She labeled it on the
slide as one of Norris's coveted " WTF objects. " (Here, WTF is
supposedly short for " widefield outlier finder, " the name of an
algorithm he'd intended to use to find such objects.)
Yet neither Norris nor members of the team followed up
on that discovery. It was only a couple of weeks later, when
Emil Lenc (CSIRO, Australia) sent a tile of EMU data to Norris,
that a second find caught Norris's attention. " He'd found
this really dramatic circle, " Norris says. " And that's when we
got excited. " That object also appeared as a ring, again spanning
an arcminute, but this time crisscrossed with fuzz.
Lenc's discovery still stands as ORC 1; Kapinska's is
ORC 2. (The two are located in the southern constellations
Pavo and Indus, respectively.) Only a year later, when putting
together a more exact chronology, did Norris realize that
Kapinska had found hers first.
RINGS, RINGS, RINGS These mark-ups show three possible
interpretations of the details revealed in a higher-resolution image of
ORC 1, taken by the MeerKAT radio array in South Africa.
" Front " ring
Another ring
sk yand tele scope .o r g * JANUARY 2025 35

http://skyandtelescope.org

Sky & Telescope - January 2025

Table of Contents for the Digital Edition of Sky & Telescope - January 2025

Contents
Sky & Telescope - January 2025 - Cover1
Sky & Telescope - January 2025 - Cover2
Sky & Telescope - January 2025 - 1
Sky & Telescope - January 2025 - Contents
Sky & Telescope - January 2025 - 3
Sky & Telescope - January 2025 - 4
Sky & Telescope - January 2025 - 5
Sky & Telescope - January 2025 - 6
Sky & Telescope - January 2025 - 7
Sky & Telescope - January 2025 - 8
Sky & Telescope - January 2025 - 9
Sky & Telescope - January 2025 - 10
Sky & Telescope - January 2025 - 11
Sky & Telescope - January 2025 - 12
Sky & Telescope - January 2025 - 13
Sky & Telescope - January 2025 - 14
Sky & Telescope - January 2025 - 15
Sky & Telescope - January 2025 - 16
Sky & Telescope - January 2025 - 17
Sky & Telescope - January 2025 - 18
Sky & Telescope - January 2025 - 19
Sky & Telescope - January 2025 - 20
Sky & Telescope - January 2025 - 21
Sky & Telescope - January 2025 - 22
Sky & Telescope - January 2025 - 23
Sky & Telescope - January 2025 - 24
Sky & Telescope - January 2025 - 25
Sky & Telescope - January 2025 - 26
Sky & Telescope - January 2025 - 27
Sky & Telescope - January 2025 - 28
Sky & Telescope - January 2025 - 29
Sky & Telescope - January 2025 - 30
Sky & Telescope - January 2025 - 31
Sky & Telescope - January 2025 - 32
Sky & Telescope - January 2025 - 33
Sky & Telescope - January 2025 - 34
Sky & Telescope - January 2025 - 35
Sky & Telescope - January 2025 - 36
Sky & Telescope - January 2025 - 37
Sky & Telescope - January 2025 - 38
Sky & Telescope - January 2025 - 39
Sky & Telescope - January 2025 - 40
Sky & Telescope - January 2025 - 41
Sky & Telescope - January 2025 - 42
Sky & Telescope - January 2025 - 43
Sky & Telescope - January 2025 - 44
Sky & Telescope - January 2025 - 45
Sky & Telescope - January 2025 - 46
Sky & Telescope - January 2025 - 47
Sky & Telescope - January 2025 - 48
Sky & Telescope - January 2025 - 49
Sky & Telescope - January 2025 - 50
Sky & Telescope - January 2025 - 51
Sky & Telescope - January 2025 - 52
Sky & Telescope - January 2025 - 53
Sky & Telescope - January 2025 - 54
Sky & Telescope - January 2025 - 55
Sky & Telescope - January 2025 - 56
Sky & Telescope - January 2025 - 57
Sky & Telescope - January 2025 - 58
Sky & Telescope - January 2025 - 59
Sky & Telescope - January 2025 - 60
Sky & Telescope - January 2025 - 61
Sky & Telescope - January 2025 - 62
Sky & Telescope - January 2025 - 63
Sky & Telescope - January 2025 - 64
Sky & Telescope - January 2025 - 65
Sky & Telescope - January 2025 - 66
Sky & Telescope - January 2025 - 67
Sky & Telescope - January 2025 - 68
Sky & Telescope - January 2025 - 69
Sky & Telescope - January 2025 - 70
Sky & Telescope - January 2025 - 71
Sky & Telescope - January 2025 - 72
Sky & Telescope - January 2025 - 73
Sky & Telescope - January 2025 - 74
Sky & Telescope - January 2025 - 75
Sky & Telescope - January 2025 - 76
Sky & Telescope - January 2025 - 77
Sky & Telescope - January 2025 - 78
Sky & Telescope - January 2025 - 79
Sky & Telescope - January 2025 - 80
Sky & Telescope - January 2025 - 81
Sky & Telescope - January 2025 - 82
Sky & Telescope - January 2025 - 83
Sky & Telescope - January 2025 - 84
Sky & Telescope - January 2025 - Cover3
Sky & Telescope - January 2025 - Cover4
Sky & Telescope - January 2025 - SGA1
Sky & Telescope - January 2025 - SGA2
Sky & Telescope - January 2025 - SGA3
Sky & Telescope - January 2025 - SGA4
Sky & Telescope - January 2025 - SGA5
Sky & Telescope - January 2025 - SGA6
Sky & Telescope - January 2025 - SGA7
Sky & Telescope - January 2025 - SGA8
Sky & Telescope - January 2025 - SGA9
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