Sky and Telescope - August 2016 - 27

IMAGE: POSS-II / CALTECH / PALOMAR OBSERVATORY / SKETCH: UWE GLAHN

M2-55

Right: Even without a filter, the view through a 27-inch reflector
at 419× displays M 2-55's annularity and knotty structure.

Challenge Targets
Some Minkowski planetaries are particularly tough
objects, where it's possible to detect a disk but it's
anything but easy. I offer three challenge objects that,
while easy enough to see as a star, will be devilishly
hard, but not impossible, to detect as a disk. M 1-1 lies
on the Andromeda-Perseus border about 2°° north of
51 Andromedae. It's tiny, just 6″ in diameter. M 1-22 in
Ophiuchus is only a little larger in listed dimension at
about 9″. Its classification implies a ring structure, but
I've yet to see annularity. M 1-22 is in a busy neighborhood between the globular cluster Messier 9 and the
open cluster Messier 23. M 4-9, 2° 41′ southwest of Eta
(η) Serpentis in Serpens Cauda, shows a ghostly disk
even without a fi lter. These three should present owners
of 8- and 10-inch scopes with a significant challenge.
Many objects have been known to mimic planetary
nebulae, and, of course, there are some misidentified
objects with Minkowski designations. I've been fooled
by a few of them. For instance, the eclipsing binary star
V471 Persei has the designation M 1-2, and my logbook
contains the description of a nebulous-looking star that
was easy to see without a filter.
The densest concentration of Minkowski planetaries
is found in Sagittarius. That constellation contains more
than 60 objects from the catalogs, with another 49 in
neighboring Scorpius and Ophiuchus. Nearly all of these
objects are tiny and well hidden among the dense star

fields of the Milky Way. This, of course, is the ultimate
challenge for the observer of Minkowski PNe. For North
American observers, the southern declinations add significantly to the difficulties, and observers who set a goal
of observing the entire catalog have their work cut out
for them. For dedicated PN fans, however, it can be a real
labor of love and a very rewarding observing project. ✦
Contributing Editor Ted Forte observes from his home near
Sierra Vista, Arizona.

M1-1

POSS-II / CALTECH / PALOMAR OBSERVATORY

CEPHEUS SIGHTS Above: M 2-55 appears elliptical or as a
slightly uneven smudge until you pump up the magnification
and throw on a filter. Look for the star-like knots in its body.

Sk yandTelescope.com August 2016

27



http://www.SkyandTelescope.com

Sky and Telescope - August 2016

Table of Contents for the Digital Edition of Sky and Telescope - August 2016

Contents
Sky and Telescope - August 2016 - Cover1
Sky and Telescope - August 2016 - Cover2
Sky and Telescope - August 2016 - 1
Sky and Telescope - August 2016 - Contents
Sky and Telescope - August 2016 - 3
Sky and Telescope - August 2016 - A
Sky and Telescope - August 2016 - B
Sky and Telescope - August 2016 - 4
Sky and Telescope - August 2016 - 5
Sky and Telescope - August 2016 - 6
Sky and Telescope - August 2016 - 7
Sky and Telescope - August 2016 - 8
Sky and Telescope - August 2016 - 9
Sky and Telescope - August 2016 - 10
Sky and Telescope - August 2016 - 11
Sky and Telescope - August 2016 - 12
Sky and Telescope - August 2016 - 13
Sky and Telescope - August 2016 - 14
Sky and Telescope - August 2016 - 15
Sky and Telescope - August 2016 - 16
Sky and Telescope - August 2016 - 17
Sky and Telescope - August 2016 - 18
Sky and Telescope - August 2016 - 19
Sky and Telescope - August 2016 - 20
Sky and Telescope - August 2016 - 21
Sky and Telescope - August 2016 - 22
Sky and Telescope - August 2016 - 23
Sky and Telescope - August 2016 - 24
Sky and Telescope - August 2016 - 25
Sky and Telescope - August 2016 - 26
Sky and Telescope - August 2016 - 27
Sky and Telescope - August 2016 - 28
Sky and Telescope - August 2016 - 29
Sky and Telescope - August 2016 - 30
Sky and Telescope - August 2016 - 31
Sky and Telescope - August 2016 - 32
Sky and Telescope - August 2016 - 33
Sky and Telescope - August 2016 - 34
Sky and Telescope - August 2016 - 35
Sky and Telescope - August 2016 - 36
Sky and Telescope - August 2016 - 37
Sky and Telescope - August 2016 - 38
Sky and Telescope - August 2016 - 39
Sky and Telescope - August 2016 - 40
Sky and Telescope - August 2016 - 41
Sky and Telescope - August 2016 - 42
Sky and Telescope - August 2016 - 43
Sky and Telescope - August 2016 - 44
Sky and Telescope - August 2016 - 45
Sky and Telescope - August 2016 - 46
Sky and Telescope - August 2016 - 47
Sky and Telescope - August 2016 - 48
Sky and Telescope - August 2016 - 49
Sky and Telescope - August 2016 - 50
Sky and Telescope - August 2016 - 51
Sky and Telescope - August 2016 - 52
Sky and Telescope - August 2016 - 53
Sky and Telescope - August 2016 - 54
Sky and Telescope - August 2016 - 55
Sky and Telescope - August 2016 - 56
Sky and Telescope - August 2016 - 57
Sky and Telescope - August 2016 - 58
Sky and Telescope - August 2016 - 59
Sky and Telescope - August 2016 - 60
Sky and Telescope - August 2016 - 61
Sky and Telescope - August 2016 - 62
Sky and Telescope - August 2016 - 63
Sky and Telescope - August 2016 - 64
Sky and Telescope - August 2016 - 65
Sky and Telescope - August 2016 - 66
Sky and Telescope - August 2016 - 67
Sky and Telescope - August 2016 - 68
Sky and Telescope - August 2016 - 69
Sky and Telescope - August 2016 - 70
Sky and Telescope - August 2016 - 71
Sky and Telescope - August 2016 - 72
Sky and Telescope - August 2016 - 73
Sky and Telescope - August 2016 - 74
Sky and Telescope - August 2016 - 75
Sky and Telescope - August 2016 - 76
Sky and Telescope - August 2016 - 77
Sky and Telescope - August 2016 - 78
Sky and Telescope - August 2016 - 79
Sky and Telescope - August 2016 - 80
Sky and Telescope - August 2016 - 81
Sky and Telescope - August 2016 - 82
Sky and Telescope - August 2016 - 83
Sky and Telescope - August 2016 - 84
Sky and Telescope - August 2016 - Cover3
Sky and Telescope - August 2016 - Cover4
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