Sky & Telescope - March 2024 - 56

MARCH 2024 OBSERVING
Suburban Stargazer
7h 50m
7h 40m
GEMINI
+30°
2371-2
σ
β
Pollux
υ
76
57
κ
64
65
ι
2
3
4
5
6
7
8
+25°
Ken's Route to
NGC 2420
GEMINI
4
5
6
7
8
9
10
11
+23°
+24°
Castor
α 7h 30m
ρ
7h 20m
κ
δ
2420
63
Wasat
2392
pOFF-ROAD IN GEMINI The author's
star-hop route to NGC 2420 starts at Kappa
(κ) Geminorum, then follows a ragged line of
dimmer stars southwestward to the target.
Along the way, the double star Σ1124 is worth
a close look to reveal the adjacent, faint triplestar
set known as VAS 14.
binary. The glaring yellowish primary
(Kappa itself) overwhelms a 10.0-magnitude
secondary 7.0″ to the southwest.
Resolving these unequal elements is too
much to ask of my 4¼-inch reflector;
however, my larger telescopes split them
starting at around 100× - the more
magnification the better.
Motoring 2° further southward, we
encounter a half-dozen 6th- to 9thmagnitude
stars in a loosely spaced
chain, 1½° long, trending southwestward.
The fifth link in this raggedy
chain is the pretty double star Struve
(Σ) 1124. The delicate double is an
almost perfectly balanced system: The
primary is magnitude 9.1; the secondary
is magnitude 9.3. Separated by 19.3″,
they resolve easily in my bigger scopes.
The 4¼-inch needs 72× for a clean split,
which is fine because the extra power
unveils a tidy little bonus.
Three pinpricks immediately north
of Σ1124 form a nearly 3′-long row,
tilted west-southwestward. The lineup
is listed in the Washington Double Star
56 MARCH 2024 * SKY & TELESCOPE
Σ1124
2420
HD 60819
7h 48m
7h 44m
Catalog as VAS 14. The middle star,
10.9-magnitude VAS 14C, lies 78.3″
north-northwest of the primary in
Σ1124 (Σ1124A). Flanking VAS 14C are
11.3-magnitude VAS 14D (westward)
and 10.4-magnitude VAS 14E (eastward).
There isn't VAS 14A or B here;
the trio as cataloged is connected to
Σ1124. Never mind the ABCs - simply
take a moment to admire this doubledubbed
trio in your scope.
Now my off-road tour gets a tad
trickier. Roughly 1
/3° west-southwest
of VAS 14 is an 8.6-magnitude star
labeled HD 61318 - the final link in
the six-star chain I mentioned earlier.
A line drawn from VAS 14 southwestward
through HD 61318, then extended
another ¼°, grazes the northern edge of
an often-overlooked deep-sky object.
Phantom Family
The open cluster NGC 2420 is only 6′
across and glows modestly at magnitude
8.3. Although it contains hundreds of
stars, none of them shine brighter than
7h 40m
7h 36m
+21°
magnitude 11. Needless to say, this
phantom family doesn't put on much of
a show in my badly light-polluted sky.
My naked-eye limit hovers around magnitude
4.2, a constant reminder that
the " deep " sky is rather shallow where I
live. Even so, I can find the phantom.
The key to success is identifying the
cluster's immediate celestial neighborhood.
NGC 2420 resides inside a slender
triangle, 16′ tall, outlined by a trio
of stars of magnitude 9.1, 9.3, and 9.7.
The slim asterism sits halfway between
the previously mentioned HD 61318
and 8.2-magnitude HD 60819 farther
southwest. The triangle is oriented
north-south, its vertex at the south end.
Moderate magnification should reveal
two 11th-magnitude stars running
northeastward from the vertex, and
two more extending westward from the
triangle's west side.
The neighborhood described above
materializes even in my 4¼-inch Newtonian
operating at 72×. The triangle stars
are easy, the others dim but definite.
+22°
VAS 14
HD 61318
Star magnitudes
Star magnitudes
Sky & Telescope - March 2024

Table of Contents for the Digital Edition of Sky & Telescope - March 2024
