Sky & Telescope - March 2025 - 56

MARCH 2025 OBSERVING
Suburban Stargazer
Chertan
Denebola
β
LEO
NGC 3628
2
3
4
5
6
7
8
9
VIRGO
3705
4 ξ
ω
+8°
HD 98388
M66
Leo Triplet
73
M65
3593
Rusty Double +12°
3810
ι
HD 98280
Σ1536
+10°
θ
3596
+14°
light is spread over an area measuring
13.1′ by 3.1′. The galaxy's overall surface
brightness works out to magnitude 13.4,
which is more than half a magnitude
dimmer than the same metric for M65
and M66. Worse for us urbanites, a
photon-blocking dust lane runs the
length of NGC 3628. I glimpsed the
elusive edge-on in my trusty 10-inch
but not the 4¼-inch.
Bonus Treats
Sometimes during our explorations of
the deep sky, we encounter small yet
pleasing star patterns we've never come
across before. The element of surprise
is one of the many reasons I enjoy starhopping
so much.
Astro-serendipity was on my side
ν
σ
+6°
80
83
τ
β
Zavijava
11h 50m
11h 40m
11h 30m
79
11h 20m
11h 10m
pLEO'S LEGS The Lion's hind legs are outlined by 4th- and 5th-magnitude stars. Those dim
markers can be used to locate two well-known spiral galaxies and several double stars. While the
visibility of the galaxies is compromised by city light pollution, the doubles are plainly visible in
backyard telescopes.
Well, sort of. They weakly surmounted
the soupy sky, appearing as whitish
nebulosities at 64×.
M66 did outshine M65, but in every
other respect the objects looked alike.
Each galaxy exhibited a condensed hub
surrounded by an extremely diffuse,
elliptical halo aligned roughly northsouth.
Increasing the magnification
didn't help matters - the lame lumps
of light simply dissolved into the soup.
Bravely, I tried to snare the galaxies
56 MARCH 2025 * SKY & TELESCOPE
using my 4¼-inch f/6 Newtonian reflector.
Applying 54×, I centered the scope
on HD 98388 and - hallelujah! - two
pale puffs emerged out of the ether.
Again, however, additional magnification
produced no improvement.
Pushing my luck, I attempted the
edge-on galaxy situated 36′ north
of M66. Oriented east-southeast by
west-northwest, NGC 3628 turns our
tandem into a trio. Problem: Although
NGC 3628 is listed at magnitude 9.5, its
3640
75
+4°
+2°
many years ago when my hop from
Theta Leonis toward M65 and M66
accidentally (or sloppily) jumped right
past 73 Leonis. In doing so, I noticed
that 73 shines at the top of a 1.5°-long
chain of half a dozen 7th- and 8thmagnitude
stars meandering southsoutheastward
down one of Leo's hind
legs. My attention was drawn to the
second-last link in the chain, where two
stars flicker at magnitudes 7.6 and 8.7,
separated by 84″. The rusty-hued combo
was obvious at low power. Oddly, my
Rusty Double doesn't appear to be cataloged
as an official double.
A proper binary system is located not
far below the chain of stars mentioned
above. The prize is 4.1-magnitude Iota
(ι) Leonis, which hangs 2° southeast
of 6.7-magnitude HD 98280, the last
link in the chain. Identified in double
star catalogs as Struve 1536 (Σ1536),
Iota harbors a 6.7-magnitude sun 2.3″
eastward. It's a tightly spaced, strongly
uneven binary. I could detect the
secondary sun in my 4¼-inch scope at
186×, provided the atmospheric seeing
was steady. The 10-inch could split
Σ1536 at 169×, and the result was truly
satisfying at 218×.
There was more scenery farther
south. Getting to the exact spot meant
a couple of biggish hops, but thankfully
they involved stars easy to see in
my 8×50 finders (and binoculars, too).
From Iota, I dropped southward 4½°
Star magnitudes

Sky & Telescope - March 2025

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