Sky and Telescope - April 2015 - 38

The Herschel Sprint
peculiar spiral with mottled and distorted arms. Largeaperture telescopes may reveal some of this structure. A
fainter, elliptical companion, IC 2982, lies immediately
west of NGC 4004, though it was not detected by Herschel. NGC 4008 is a brighter, though uninspiring lenticular object. NGC 4017, paired with NGC 4016, presents as
an intriguing barred spiral that may be interacting with
an irregular companion. Herschel may have seen some
structure in NGC 4017, calling it: "Faint, pretty large,
extended, brighter towards the following side." Together,
these two galaxies are also known as Arp 305.
After chalking up NGC 4080 and NGC 4104 in
modern Coma Berenices, things became hectic for the
Herschels. Two compact quartets came into view in quick
h m
4514 12 30

+29°
+29°

12h 25m

12h 20m

12h 15m 4173

4286 4283
4278
4310

4495

12h 10m

4131
4132
4169
4134

4175

4174
4448

4375
4196
4251

+28°
4393

4275

4475

+27°

4185

+28°

COMA
BERENICES

+27°
4146

12h 25m

5 6 7 8 9 10

Star magnitudes

12h 20m

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COMA BERENICES. Objects labeled in yellow were discovered during Herschel's previous sweeps. Green labels mark
objects he inadvertently duplicated in his catalogue.

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succession. The ﬁrst was a linear triplet formed by NGC
4131, NGC 4132, and NGC 4134. The brightest and
most southerly object was the inclined, multi-arm spiral
NGC 4134. The other two galaxies were fainter and in the
register, Caroline wrote, "Two of three, the place is that of
II. 371 [NGC 4134]. Both very faint, much extended. A 4th
suspected." This fourth object may have been MCG +5-2924, a faint galaxy with an elongated, relaxed spiral form,
immediately east-northeast of NGC 4132.
Less than four minutes later, the Herschels recorded
all four members of what is now known as the Hickson
61 galaxy group. The description of the faintest three
objects reads, "Three of a quartile. The place is that
of II. 372 [NGC 4173]. All very faint, very small and all
within 3′." NGC 4169, probably the easiest to spot of "the
quartile," is a lenticular galaxy that creates an oval glow
in the ﬁeld of view. NGC 4173, the largest, but also the
most challenging target in the group, may not be a true
member, as its radial velocity is almost 3000 km/s less
than that of the other galaxies.
Sweeping south, William came upon another wide
physical pair of galaxies, NGC 4185 and NGC 4196 -
and something of a mystery as well. Herschel noted a
third object, NGC 4209, which he described as "faint,
pretty small." Yet, no galaxy exists at the recorded position. Conventional wisdom assumes that NGC 4209
duplicated the observation of NGC 4185, even though Herschel described that galaxy as "faint, large, brighter to the
middle." The NGC authority Wolfgang Steinicke equates
NGC 4209 with a faint star at the recorded position. Considering that William might have been rushing things at
this point (recording ten nebulae in only four minutes),
it's easy to imagine him mistaking a faint star for a small
nebula. According to Dreyer's The Scientiﬁc Papers of Sir
14h 10m

14h 00m

13h 50m

5642

+30°

CANES
V E N AT I C I
5735

+28°

BOOTES

5635

5594

+26°
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14h 40m

April 2015 sky & telescope

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Sky and Telescope - April 2015

Table of Contents for the Digital Edition of Sky and Telescope - April 2015