From the July 2004 issue

Deep-sky tour challenges for autumn

OK, you did the easy items — here are a few to test your observing skills.
By | Published: July 27, 2004 | Last updated on May 18, 2023
M33
Cliff Wright used an 18-inch Centurion reflector at f/2.8 and a SBIG ST8 CCD camera to image M33. This image was taken from Chiefland, Florida.
Cliff Wright
To chase down these objects, you’ll need a telescope (for most of them), an observing site with a clear view of the sky plus a low level of man-made skyglow, and a good star atlas. For the latter, try Sky Atlas 2000.0 or Norton’s Star Atlas. (Patience won’t go amiss, either.)

M33
The Andromeda Galaxy, M31, is one of the easiest deep-sky objects for binoculars, but another nearby spiral galaxy, M33, is among the most difficult. Lying in the small constellation Triangulum, between Andromeda and Aries, M33 can be seen in dark, clear skies by eye (but not easily!). The galaxy is presented face-on to us and its pale light spreads out over an area of sky larger than the Full Moon. A large telescope will be needed to trace its spiral arms.

View M33 with Star Dome

NGC 1300
The bar across the center of galaxy NGC 1300 extends more than 150,000 light-years.
N. Bies, E. Hernandez/A. Block / NOAO / AURA / NSF
NGC 1300
Barred spiral galaxies are notoriously difficult objects in which to see structure, but three of the best lie conveniently placed in the southern sky during late summer.

NGC 1300 in Eridanus is familiar from pictures in books. Moderate apertures will show the bright nucleus and the central bar, but a 12-inch (300 mm) scope probably will be needed to trace the spiral arms.

View NGC 1300 with Star Dome

NGC 1365
Sporting two massive spiral arms and lots of star formation, galaxy NGC 1365 lies about 58 million light-years away.
S. Quirk
NGC 1365
Another barred spiral galaxy, NGC 1365 in neighboring Fornax sports two massive spiral arms and lots of star formation, galaxy NGC 1365 lies about 58 million light-years away.

View NGC 1365 with Star Dome

NGC 1097
Lying some 50 million light-years away, the barred spiral galaxy NGC 1097 is a relatively strong radio source and contains a lot of warm dust. The oval blob at upper right is a small elliptical galaxy interacting with the main galaxy.
Digital Sky Survey / STScI
NGC 1097
Another barred spiral in Fornax, NGC 1097 shines slightly brighter than NGC 1365. It is a relatively strong radio source and contains a lot of warm dust. The oval blob at upper right is a small elliptical galaxy interacting with the main galaxy.

View NGC 1097 with Star Dome

NGC 7331
Spiral galaxy NGC 7331 is among 18 galaxies selected to be used in calibrating the size of the universe using Cepheid variable stars. It lies 49 million light-years away.
N. and J. Goldring / A. Block / NOAO / AURA / NSF
NGC 7331
NGC 7331 is an edge-on spiral galaxy in Pegasus that’s visible with a 4-inch telescope as an elongated smudge but is better seen with larger instruments.

View NGC 7331 with Star Dome

M74
Also known as NGC 628, M74 is about 35 million light-years away in the constellation Pisces the Fishes. It is estimated to be the home of about 100 billion stars, making it slightly smaller than our Milky Way Galaxy. This view is a composite of images taken on the night of August 13-14, 2001, with the 8-meter Gemini North telescope and the Gemini Multi-Object Spectrometer.
Gemini Observatory / GMOS Team
M74
M74 is a face-on spiral galaxy easy to locate near the brightest star in Pisces, Eta (&eta) Piscium. Its rounded shape can be glimpsed in small telescopes with low powers but apertures of 6 inches (150 mm) or more are needed to see any trace of spiral structure. Views of this galaxy depend strongly on sky conditions.

View M74 with Star Dome

NGC 7243
Lying about 2,800 light-years away, open star cluster NGC 7243 appears sparsely populated.
Digital Sky Survey / STScI
NGC 7243
NGC 7243 is an open cluster in the faint northern constellation Lacerta. The cluster consists of a few dozen stars of 8th magnitude and fainter scattered over an area equivalent in size to the Full Moon.

View NGC 7243 with Star Dome

M76
A planetary nebula such as M76 is the cloud of gas shed by a star as it evolves into a white dwarf; M76 lies about 3,400 light-years away.
M. Germano
M76
M76 in Perseus is reputedly the faintest object in Charles Messier’s catalog. It is a planetary nebula popularly known as the Little Dumbbell and can be found with a 4-inch scope on a dark night. Each of its lobes appears as a separate object.

View M76 with Star Dome