Sky & Telescope - March 2022 - 25

by an obscuring dust lane. Three stars are involved at the
galaxy's southeastern end. In my 30-inch scope, I detect a
fainter northern arm and two emission knots, designated
IC 3551 and IC 3555. I didn't spot the other knots associated
with this galaxy that have IC designations.
Lying some 27′ northeast of Gamma Comae, NGC 4448
is a barred spiral with a prominent, oval-shaped core that's
easily within reach of an 8-inch scope. A fainter, oval ring
surrounds the core that I can just detect a tantalizing hint of
with the 30-inch. Can you see it?
Go back to Gamma Comae and from there slew 1.9° west
to find NGC 4251, a spindle-shaped lenticular galaxy with
a bright, elongated core. Just 1½° northeast of the galaxy is
Hickson 61. This is one of my favorite Hickson groups and is
sometimes called The Box because of the rectangular arrangement
of its four bright members: NGC 4173, NGC 4169, NGC
4174, and NGC 4175. NGC 4173, the edge-on spiral that
forms the northern corner of the box shape, is a foreground
object since it lies at one-third the distance of the other three.
In angular size, it's the largest galaxy in the group. An interesting
side note is that German astronomer Heinrich Louis
d'Arrest " discovered " two other nebulae close to The Box but
outside of the group that Herschel saw. However, those two
objects - NGC 4170 and NGC 4171 - apparently don't exist.
It's quite possible that poor seeing blurred some nearby stars,
misleading d'Arrest to log them as nebulous objects.
Another object that's visible in an 8-inch scope is the
elliptical galaxy NGC 4278, which is the most prominent
member of a trio that includes NGC 4283 and NGC 4286.
You'll find all three 1¾° northwest of Gamma Comae. Herschel
discovered NGC 4278 and NGC 4283 twice. The first
time he came across these targets during sweep 387 on March
13, 1785, he recorded them as II 322 and II 323 (along with
the third galaxy III 300, NGC 4286). When Herschel encountered
the pair again on April 11, 1785, he assumed they were
new and logged them as I 90 and II 377.
Let's step away from Coma Berenices for a while and head
toward the southernmost reaches of Ursa Major where we
find NGC 3550 and NGC 3552 - two of the brightest galaxies
in Abell 1185, a rich galaxy cluster that lies about 500
million light-years away. Herschel saw them as very faint and
very small and even noted that he wouldn't have picked up
the more southerly object, NGC 3552, had it not been close to
the more prominent NGC 3550. I saw NGC 3550 fairly easily
in the 18-inch, while NGC 3552 was considerably more difficult
and not always distinct, but rather immersed in a haze
of very faint nebulosity. My 30-inch can separate NGC 3552
from adjacent MCG 5-27-4 lying some 42″ to the southwest,
which Herschel didn't note. This galaxy is most likely the
object that French astronomer Camille Guillaume Bigourdan
found 100 years after Herschel's discovery and should
probably be designated NGC 3553. Since Bigourdan confused
his discovery with NGC 3552, doubt lingers as to which new
object he observed. These galaxies are about 3¼° southwest of
Xi (ξ) Ursae Majoris.
Duplicitous Duos
Among the objects that Herschel discovered on this remarkable
night, uncertainties remain about the identities of several, and
there are duplications worth noting.
Many of the galaxies Herschel swept up on April 11, 1785,
belong to the Coma Cluster and count among the brightest
members of that group of more than 1,000 galaxies. Of the 20 or
so that he identified that night, the easiest to bag are NGC 4889
and NGC 4874, which together comprise the core of the rich
cluster. Your starting point is 4.2-magnitude Beta (β) Comae,
and from there you'll slide 22
/3° due west to find this duo.
NGC 3550
NGC 3552
COSMIC CHAOS Abell 1185 teems with galaxies of all shapes and
sizes, many of which are drifting alarmingly close to one another. Several
galaxies have already been ripped apart. Arp 105 (in the left-hand side
of the image) is the result of a collision between a spiral and an elliptical,
and the bluish feature stretching northward is a plume of ejected stars.
sk yand tele scope .o r g * MARCH 2022 25
NICK PAVELCHAK
http://skyandtelescope.org
Sky & Telescope - March 2022

Table of Contents for the Digital Edition of Sky & Telescope - March 2022
