The dominant object of late autumn is M31, the Andromeda
Galaxy, by far the biggest, brightest, and most prominent
galaxy visible from locations north of the tropics. If
you can tear your eyes from M31 and its companions M32
and M110, the octile of the sky from RA 0 to RA 3 also
contains a smorgasbord of other interesting objects:
two of the galaxies that are hardest to see under heavy
light pollution (M33 and M74), the nearest galaxy with
an active nucleus (M77), the faintest of the Messier
objects (M76), and a very bright albeit sparse open
cluster (M34). Here is the complete list of objects
for this section, all of the Messier objects from RA 0
to RA 3 minus M103, which was covered in the previous
For a key to this table, see
Key to the Tables.
With the exception of M77 and M74, all of these objects have
far northerly declinations, and so remain well-placed for a
very long time for observers in the North Temperate Zone,
starting typically in the late summer and extending well
into the winter, or even the early spring.
Several of the objects listed in the early autumn section
are also far north, and remain visible throughout autumn.
And M45, the Pleiades, harbinger of the winter sky, can
be seen rising in the east throughout autumn from northern
M31, M32, and M110
M31, the Andromeda Galaxy, is the largest and brightest
member of the Local Group of galaxies, with our own Milky
Way not far behind. It is also the only galaxy which is
genuinely easy to see from the Northern Hemisphere, even
with tiny instruments and even under heavy light pollution.
The two Magellanic Clouds, our nearest galactic neighbors,
are much brighter even than M31, but they are visible only
from the Southern Hemisphere.
Like our own Milky Way, M31 is a spiral galaxy, but we see
it from a rather awkward angle, which makes the spiral
structure hard to discern even in the best astrophotographs.
Some galaxies, like M33, M51, M83, and M101 are face-on
spirals oriented nearly perpendicular to our line of sight,
so that we see the spiral pattern laid out neatly along the
sky. Others, like M104, are edge-on spirals oriented
nearly parallel to our line of sight, so that we see them
as thin lines across the sky with a central bulge in the
middle. We see M31 neither face on nor edge on, but at a
shallow angle, so that the face of the disk is visible,
but appears as a highly elongated ellipse. The dark lanes
between the spiral arms are visible, but barely.
M32 and M110 are the two brightest satellite galaxies of M31,
as the Magellanic Clouds are satellites of our Milky Way.
M32 and M110 are both classified as elliptical galaxies,
and they are nearly identical in total brightness, but the
similarities stop there. M32 is tiny and intense, with an
extremely bright core, while M110 is huge and diffuse,
with no core worthy of the name. They rank near the top
and bottom of all the Messier galaxies in surface brightness.
There are two classic ways to locate M31. For people not
familiar with the sky who are using wide-field instruments
like binoculars, M31 can be located with respect to the
Pole Star and Cassiopeia. A line from Polaris through Alpha
Cassiopeiae, continued on for 50% of that distance, lands
almost directly atop M31. But since this is a 15-degree
jump through the sky, you are unlikely to land M31 inside
a telescopic field of view using this method.
A much more precise method is to start with the bright star
Beta Andromedae, just 8 degrees from M31. It is well worth
learning the constellations of Andromeda and Pegasus, which
dominate the autumn sky. They are connected through the
star Alpha Andromedae (Alpheratz), which is tecnically in
Andromeda but is also one of the four stars composing the
Great Square of Pegasus. The whole thing forms a vast
asterism which I like to think of as the Truly Gigantic
Dipper, shaped very much like the Big Dipper, but twice
as big. Projections from Polaris through the stars of
Cassiopeia, and then continued for an equal distance,
very nearly outline the bright stars of Andromeda.
In decent urban skies of better, you should be able to see
Mu Andromedae, the mag 3.9 star 4 degrees NW of Beta And.
A line from Beta through Mu and continued another 4 degrees
lands directly atop M31. Slightly SE of M31 is Nu Andromedae,
mag 4.5. If you can see Nu, it is likely that you can also
see M31 itself with your unaided eye. It sometimes appears
to me as a faint, smallish cloud, and sometimes as a nearly
stellar object. It is worth a look, because at nearly 3
million light years, M31 is the most distant object visible
to the naked eye without major effort. If you cannot see
M31 without aid, even the tiniest optical instrument, such
as opera glasses, should show it as a faint cloud of light.
Under urban skies, little more than the core of M31 is visible.
In my 70mm scope, it shows much the same at all powers, as
a very bright, slightly elliptical patch, about 5' by 4'.
I can see somewhat more of the core in my 178mm scope,
especially at higher power, plus a very faint extension
to the SSW. In the larger scope, it is also apparent that
there is an intense, nearly stellar nucleus near the center.
Under suburban skies, much more of M31 is visible in both scopes.
The core is embedded in a huge faint glow about one degree long
from SW to NE, but much narrower, perhaps 6' to 8' at the widest
in the 70mm scope and 10' to 12' wide in the 178mm scope, and
tapering towards the ends. M31 is a spiral galaxy, and this
extended glow is the inner part of the disk. If you correlate
the telescopic view in the suburbs to a photograph, it will be
apparent that you are seeing the portion of the disk inside the
first dark lane, the hub where the spiral arms join together.
The extended glow is brighter on the SW side of the core, but
extends much farther on the NE side, well out of the field at
60X when the core is centered. To see maximum detail, I find
it advisable to use fairly high magnifications, at least 80X or
100X in my 178mm scope, and scan around the galaxy, seeing only
a small part at one time. However, the low-power view, fitting
as much as possible of the galaxy and its companions, is equally
rewarding in a different way.
In the 178mm scope under suburban skies, it is apparent that
the extended disk stops much more abruptly on the NW edge than
on the SE edge. This is due to the inner dust lane, which
blots out the disk quite effectively. Under darker skies,
you can see another much fainter patch of light on the NW
side of the inner dust lane, then a second much subtler dust
lane to the NW of that, and after that, only the faintest
hint of light.
M32 is visible about half a degree due S of M31's core,
forming a striking, nearly rectangular shape with three
nearby stars of similar brightness. M32 is easy to see
even in very small scopes and under heavy light pollution,
but at low magnifications, it can be hard to distinguish
from a star. It appears as a point or tiny circle of
bright light, with a slightly hairy or fuzzy appearance.
Some people believe that the highly condensed appearance
of M32 is due to the fact that the outer portions of this
galaxy have been stripped away by the tidal forces of its
much bigger neighbor. In fact, M32 appears very much like
an enormous globular cluster.
Under dark skies, huge M110 is much more prominent than tiny
M32, but it is nearly invisible under serious light pollution
due to its low surface brightness and the almost complete
absence of a bright central core to grab the eye. In fact,
I sometimes think that M110 is the hardest of all the Messier
objects to see under very bright skies. All three galaxies
show easily together in one low-power field under dark skies,
but under bright skies, it is better to use fairly high
magnification, and to starhop to M110's presumed location
from M31's core, then start applying averted vision.
Seeing M110 under urban skies is a real feat. It appears as
an extremely subtle, elusive patch, barely brighter than the
background, about 5' by 3', extended N-S. Because M110's
difficulty is due almost entirely to low surface brightness
and not low total brightness, it is very nearly as easy (or
hard) to see in my 70mm scope as in my 178mm scope.
M110 is still subtle under suburban skies, but fairly
obvious once you have found it, a nearly featureless patch
of light, uniformly bright, about 6' by 4' or perhaps slightly
larger, with no clearly defined center or edges. Again, the
view is quite similar in my 70mm scope and my 178mm scope.
Our Local Group of galaxies is dominated by three big spiral
galaxies: M31, the Milky Way, and M33. M33 is much the
smallest and faintest of the three, but it is still quite
a bit bigger and brighter than the average galaxy. M33
is unusual among spiral galaxies in that it does not seem
to have a massive black hole at the center. This may be
related to the fact that its central core is unusually
small and faint compared to the brightness of the disk.
M33 is quite close in space to M31, which is reflected in
the fact that they appear quite close in the sky from our
perspective, but it is not quite close enough to count as
a satellite galaxy.
Unlike M31, M33 happens to be oriented nearly perpendicular
to our line of sight, so that the spiral pattern is clearly
visible in astrophotographs, or when M33 is seen through
a medium-to-large telescope under truly dark skies. One
of my proudest feats of suburban observing was detecting
unmistakeable signs of the spiral pattern in my 178mm scope.
Because of its proximity to our Milky Way, M33 is second
highest among all of the Messier galaxies in total
brightness, but due to its enormous size, it also ranks
third from the bottom in surface brightness. This makes
M33's visibility famously paradoxical. Under dark skies,
M33 is one of the easiest galaxies to see in small
instruments; it is not especially hard to see with the
unaided eye, and is very easy to see in small binoculars.
(Easier in binoculars than in a telescope, many people say.)
Under even modest light pollution, however, M33 is
notoriously difficult to see even in large instruments,
due to its low surface brightness.
Actually, I do not find M33 quite as hard to see as the
surface brightness would predict. Partly, no doubt, that
is because the theoretical size of 71 by 42 arcminutes
grossly over-states what one sees through a telescope.
Yes, M33 is enormous, but even under superb skies, M33
appears no bigger to me than 40 by 25 arcminutes, less than
one third of the size as determined from photographs.
Moreover, although M33's core is abnormally faint
compared to the galaxy as a whole, it is big enough and
bright enough to show up reasonably well even under
urban skies unlike, say, the core of M101.
Given M33's subtle appearance under urban or suburban skies,
it is definitely advisable to starhop to it rather than
using a point-and-shoot method. The nearest reasonably
bright star is Alpha Trianguli. Under good suburban skies,
Alpha can be seen to form an attractive elongated triangle
together with Beta and Gamma Trianguli to the E, but this
triangle does not stand out well under urban skies. The
triangle is just small enough to fit in the field of
standard 7X binoculars, which will also neatly split
mag 4.9 Delta Trianguli from nearby Gamma. If you cannot
make out the triangle, Alpha can be found 2/5 of the way
from bright Alpha Arietis to Beta Andromedae, the
jumping-off star for M31. From Alpha Tri, it is a
modest but slightly awkward starhop over 4 degrees
of fairly blank sky to M33.
Since M33 itself can be hard to discern, you should look
first for an elegant quadrangle about 35' long and 25' wide
composed of three mag 8.1 stars and a mag 9.3 star at the
N corner. The core of M31 lies slightly to the E of the
center of this quadrangle.
Under urban skies, M33 shows best at moderately low magnification,
around 20X - 30X in my 70mm scope or 40X - 80X in my 178mm scope.
It tends to fade out at higher powers. What I see in both scopes
is a large, vague blob of light about 10' by 8' elongated N-S,
with no clear center or edges. It swims into ghostly existence
when I scan with averted vision, and disappears when I look
directly at it.
M33 is much easier to make out under suburban skies, although it
still shows best with averted vision. In fact, M33 is not
terribly hard to see in my 7x35 binoculars under suburban skies,
not much harder than in my telescopes. Although easier to
see, the view in my 70mm scope is not much different under
suburban skies than under urban skies. The 178mm scope,
however, begins to reveal significant additional detail.
At first, the impression is just of a moderately faint 5'
circle surrounded by a much fainter cloud about twice
that diameter and slightly elongated N-S. Then, scanning
methodically with averted vision at 100X, I see a smaller
and fainter concentration about 10' S of the core, and a
broad triangle of extremely faint light stretching through
that secondary concentration and pointing S. On the N side,
I see a very faint, fairly thin thread of light reaching
first NE and then bending almost due E. Comparing this
impression to the photographs, I see that the E edge of
the triangle on the S is one of the spiral arms, and the
ethereal thread to the N is the other.
Not far from the end of the N arm, but a little farther out,
some 12' NNE of the core, is a truly extraordinary object:
the extragalactic emission nebula NGC 604. It is actually
quite easy to see in my 178mm scope even under urban skies,
in some sense easier than M33 itself, because it has very
high surface brightness. However, it is also easy to miss
because it lies surprisingly far from the central part of
M33, and easy to overlook because it appears incredibly
small, barely non-stellar even at 100X.
NGC 604 is an emission nebula within the N arm of M33,
an object very much like the Orion Nebula, but some
1500 times as distant, and incredibly much bigger and
brighter to be so readily visible at such an enormous
distance. Indeed, NGC 604 is one of the inherently
brightest emission nebulae known in the entire universe.
The galaxy M74 is a strong contender for the title of hardest
Messier object to see. It is low both in total brightness and
in surface brightness, making it hard both for small instruments
under dark skies and for large instruments under bright skies.
It also has an abnormally small and faint core compared to
the rest of the galaxy. If you ever get to see it with a
really big scope under truly dark skies, it will be apparent
that M74 is a face-on spiral with faint, tightly wound arms
studded with emission areas, very much like M101 but on a
much smaller scale.
Fortunately, M74 is quite easy to locate, being just 1.3 degrees
ENE of mag 3.6 Eta Piscium, and forming a nearly equilateral
triangle with that star and mag 6.2 101 Piscium to the S.
If you have trouble finding Eta Psc, first find Aries, the
most prominent constellation in this part of the sky. A
line from Alpha Arietis through Beta Arietis points
slightly N of Eta Psc.
Because M74 is unlikely to be apparent at first sight, it is
a good idea to first locate the line of 5 stars ranging from
mag 10.5 to mag 12.0 slanting from 17' due E of M74 to 20' NW.
Then you must apply averted vision in the area S of the
largest gap in that line of stars.
In my 70mm scope, M74 is difficult under dark skies, extremely
difficult under suburban skies, and invisible under urban skies.
It shows up best at around 60X, and requires both averted vision
and carefully controlled breathing. When seen, it is actually
fairly large, several arcminutes across and nearly circular.
I might think that the suburban view was an illusion if not
for the fact that it moves when I move the telescope. Moving
the scope also helps the object appear in the first place.
M74 is nearly as difficult using my 178mm scope in the city.
Again, it responds best to fairly high power (120X or higher),
and again it requires averted vision and controlled breathing.
M74 is much easier in the 178mm scope under suburban skies.
It still requires averted vision, but it is reasonably solid
once seen, and less prone to fade out unexpectedly. The best
view under suburban skies is at somewhat lower power, around
80X, where M74 appears as a vague featureless circle about 4'
M76 is another notoriously difficult Messier object, but its
difficulty lies entirely in low total brightness; it is near
the top in terms of surface brightness. Therefore, M76 is
quite hard to see in small instruments under any conditions,
but is quite easy and attractive in large scopes even under
very bright skies. M76 is a planetary nebula, shaped quite
similarly to M27 but much smaller and with somewhat higher
surface brightness. Hence M76's nickname of the Little
Dumbbell, where M27 is just the Dumbbell.
M76 lies just one degree N of the mag 4.0 star Phi Persei.
If you cannot see Phi Per directly, try looking first for
mag 3.6 51 And 2 degrees to its SSW. A mag 7.8 star lies
just 5' S of Phi Per, and a line from that star through
Phi Per lands directly atop M76. Even if you cannot see
M76 itself immediately, the field is easy to recognize by
the reddish mag 6.7 star 13' to the ESE of M76 and the
mag 9.5 star 8' to the WSW. Both stars fit easily with
M76 even in a high-power field.
I have several times tried and failed to see M76 in my 70mm
scope under urban skies; apparently, it is just too faint
to detect under such conditions. Using the 70mm scope in
the suburbs, M76 is quite faint, requiring averted vision,
but unmistakeable. It appears very small and has no hint
of detail except a slight elongation N-S. The best view
is at around 60X.
M76 is quite easy to see in my 178mm scope, readily
perceptible with direct vision even at low powers and
under heavy light pollution. The best view is at high
power, around 120X, where it appears as a bold, clear
dumbell or hourglass shape, about 2' by 1.5' elongated
NNW to SSE. The shape is marginally clearer when I use
my UHC filter, especially under urban skies.
M34 is a large, bright, coarse open cluster, a pleasant change
from faint galaxies and miniscule planetary nebulae. It shows
well under bright skies and in small instruments, and is fairly
easy to see with the unaided eye under exurban or rural skies.
M34 is fairly easy to find by the point-and-shoot method, lying
about 1 degree N of a line connecting Beta Persei (Algol) and
Gamma Andromedae (Almach), about 40% of the way from the former
to the latter. Both Algol and Almach are unusual stars. Algol
(meaning The Demon) shines at mag 2.1 most of the time, but for
10 hours every 3 days, it slowly fades to mag 3.4 and then
returns to its normal brightness. This variation is due to
an unseen companion which orbits around the primary star and
periodically passes between us and the primary, blocking some
of the light. Almach is an attractive wide double, easily
split at 60X, with a blueish secondary about 2.5 magnitudes
fainter than the yellowish primary.
If you cannot find M34 by point-and-shoot, you are faced with
a rather onerous 6-degree starhop from Algol, as no reasonably
bright star lies significantly nearer.
Although M34 is quite bright, its stars are scattered over
more than half a degree of sky, and the background stars are
also fairly rich. Therefore, M34 stands out best at low
power, which compresses its stars and shows them off against
the widest possible background. M34 is small and tight in
my 7x35 binoculars, especially under suburban skies or better,
where five of the stars resolve easily.
The best compromise between framing and seeing detail seems
to be around 60X both in my 70mm scope and in my 178mm scope.
About two dozen stars in a 35' circle are visible in the
smaller scope at that power, but some of them are extremely
faint under urban skies. In the 178mm scope, some three
dozen stars are visible in the same area.
Near the center of the cluster is a U-shaped asterism of 8
mag 8 and mag 9 stars, open to the ESE, about 6' by 4'.
At the NW end of the U is the attractive double star John
Herschel 1123, with nearly equal mag 8 components separated
by 20", and fairly easily split even at 16X. This double star
also forms one corner of a tiny dipper-shaped asterism of
mag 9 and mag 10 stars lying within the U.
M77 is a Seyfert galaxy, akin to a quasar but not
so extreme, with much or most of its radiation emitted by
an active nucleus whose size is infinitessimal compared
to the galaxy as a whole. According to current theories,
the nucleus is powered by a dense cloud of gas spiralling
into a black hole.
Because of the active nucleus, M77 has high surface
brightness and an intensely bright core, making it
readily visible even under very heavy light pollution.
However, light pollution can obliterate the outer
disk, making it hard to distinguish M77 from a star.
M77 lies one degree WSW of Delta Ceti, a mag 4.1 star
that can be rather hard to locate under bright skies.
If in doubt, the best place to start is with Alpha Ceti,
a reddish mag 2.5 star that is much the brightest in that
part of the sky. Starting with Alpha, it should be easy
to locate mag 3.5 Beta Ceti some five degrees to the W,
and possibly some of the four fainter stars which compose
the head of Cetus, the Whale, together with Alpha and
Beta. 7x binoculars help a lot in making out the head,
although they won't quite fit the whole thing in one
field of view. Delta Cet lies 3 degrees SSW of Beta.
If you cannot see M77 immediately one degree ESE of
Delta Cet, look first for the line of mag 9 stars just
to its NE. M77 lies just where one might expect a
fourth star to lie if the line contained four stars.
In my 70mm scope, M77 is a bit hard to see under urban skies,
requiring averted vision at 60X. It is considerably easier
under suburban skies, where direct vision suffices. In both
cases, it shows as a faint, slightly hairy star.
M77 shows much better in my 178mm scope, which has enough
aperture to make M77's core appear like a brightish star.
To confuse matters, there is a real mag 10.8 star, nearly
identical in brightness to M77's core, lying just a couple
of arcminutes to the E. M77's core is surrounded by a
faint haze some 3' in diameter, nearly reaching to the
neighboring star. The view is nearly identical in the
city and the suburbs, except that the haze is more
pronounced in the suburbs.