Sky and Telescope - February 2016 - 30

Circumpolar Galaxies
mechanically diﬃcult to operate his 18.7-inch (20-foot
focal length) telescope and record accurate positions in
this direction. John Herschel fared no better: with only
two exceptions, one being NGC 188, his discoveries were
all south of +80°° declination.
Albert Marth, observing in the mid-1860s from Malta
with William Lassell's 48-inch equatorial reﬂector, stayed
south of the zenith while discovering nearly 600 "nebulae." Starting in 1870, Édouard Stephan began a systematic search for nebulae using the 31-inch silver-on-glass
Foucault reﬂector at the Marseille Observatory. During
the next 15 years, he netted over 400 new objects, but his
observations were also constrained between -12° and
+46° declination. So by the time John Dreyer compiled
the New General Catalogue in 1888, the extreme north
celestial cap was largely "cosmos incognito."
The nearest NGC galaxy to the pole (just under 1°
away) is NGC 3172, which John Herschel discovered
on October 4, 1831. He dubbed it "Polarissima" but later
modiﬁed the nickname to "Polarissima Borealis" to
distinguish it from "Polarissima Australis" (NGC 2573).
He found the latter only ½° from the south celestial pole
while observing from the Cape of Good Hope.
Through my 18-inch at 285× Polarissima Borealis
appears as a pale patch about 0.4′ in diameter, enveloping a brighter core. A 13th-magnitude star lies 1.5′
northwest. PGC 36268, a challenging 16th-magnitude
companion 1.6′ away, is on the ragged edge of visibility
and diﬃcult to conﬁrm. NGC 3172 will probably require
a 10-inch or larger scope, but I'd like to hear your results.
German astronomer Wilhelm Tempel discovered
magnitude-13.2 NGC 1544 in 1876 with an 11-inch Amici
refractor at the Arcetri Observatory in Florence, Italy. The
second most northerly NGC galaxy at +86° declination,

NGC 1544 is a loner with no signiﬁcant galactic neighbors, at least none within a couple of degrees. Overall,
it's fairly faint and small, but the 0.4′ halo sharply
concentrates into a bright, nearly stellar nucleus. A pair
of 14.5-magnitude stars with a 10″ separation is pinned
against the north edge and a wider 18″ duo rests oﬀ the
northwest side.
The most interesting region for galaxy hunting surrounds NGC 2276 and NGC 2300, a disrupted spiral
and the elliptical companion 6′ to its southeast. Halton
Arp cataloged the pair as Arp 114 in his 1966 Atlas of
Peculiar Galaxies, labeling NGC 2276 as Arp 25 due to
its disrupted arms. In addition, these are considered
the two brightest members of LGG 145 (Lyon Groups of
Galaxies). The group resides at a distance of 100 million
light-years and includes the concentration of galaxies
depicted in the Uranometria atlas.
August Winnecke, director of the Strasbourg Observatory, discovered magnitude-11.4 NGC 2276 in June
1876 using a 6.4-inch refractor. Winnecke recorded it
as "faint, 1′ diameter, barely compressed." Through
my 18-inch, I found a moderately bright, asymmetric
2′ glow that intensiﬁes slightly towards the center. The
halo is dappled with a few faint H II knots, the brightest at the northwest edge, and with careful study I had a
strong impression of the spiral structure. An annoying
8th-magnitude star is parked 2.3′ west-southwest of the
galaxy; you may ﬁnd it helpful to keep it just outside the
edge of the ﬁeld of view.
POLARISSIMA BOREALIS The most familiar northern galaxy
is NGC 3172, which appears as a circular glow about 1°° below
the celestial north pole. Less well-known is PGC 36268, a tough
target even under ideal observing conditions.

HD 51802

URSA
MINOR

PGC 20191
PGC 21210

UGC 3528A
UGC 3536A

CEPHEUS

PGC 23961

IC 499

+86°

UGC 3336

UGC 4348
2276
2300

IC 512
UGC 4297

UGC 3661
UGC 3654
NGC 3172

Star magnitudes

PGC 21817
6
7
8
9
10
11

IC 455

IC 469

+85°

UGC 3670

PGC 36268

PGC 23621

UGC 3993

CAMELOPARDALIS

UGC 4078

2268
+84°
8h 20m

8h 00m

7h 40m

7h 20m

7h 00m

6h 40m

6h 20m
DAVID RATLEDGE

Februar y 2016 sky & telescope

Sky and Telescope - February 2016

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