Sky & Telescope - December 2023 - 20

Observing Challenge
be successful. Ann emailed to let me know that fortunately
things went smoothly, and she'd collected the data on
NGC 1262. What an enormous relief!
It was now up to Stephen Odewahn to work his magic. His
next step was to reduce the spectroscopic data and measure
the redshift. With much anticipation, I waited for Stephen's
results. I was excited when I received his email saying he
had identified six lines in the spectrum. The data showed
NGC 1262 had a radial velocity of 15,169 km/s, corresponding
to a redshift of z = 0.0506. Assuming a Hubble constant
(H0) of 69.6, its light-travel time is only 686 million years. It
looks like Steve's and my hunch was correct - NGC 1262 is
nowhere near the most distant NGC galaxy.
The Champion
With NGC 1262 knocked off its perch, the most distant
visually discovered galaxy on our list is now 15.6-magnitude
NGC 5609 with a light-travel time of 1.32 billion years.
Irish engineer Bindon Blood Stoney uncovered this remote
galaxy on March 1, 1851. Between 1850 and 1852, Stoney
was observing assistant to William Parsons, the Third Earl of
Rosse. Using the Earl's 72-inch Leviathan, he discovered 105
NGC objects and eight that appeared in the IC.
Stoney was examining NGC 5614 for possible spiral
structure or resolution into stars when he found three faint
nebulae nearby: NGC 5609, NGC 5613, and NGC 5615. He
THE FIELD OF NGC 5609 The current record-holder for the most
distant, visually observed galaxy is NGC 5609, which lies at a distance
of 1.32 billion light-years. Spend some time with nearby NGC 5614, a
face-on spiral at a distance of " merely " 180 million light-years. You can
catch these targets in the morning hours later in winter; otherwise, you'll
have to wait for spring to snag them in the evenings. Aperture and
magnification used for the sketches are noted.
sketched the field and placed the new objects correctly around
NGC 5614, but he had no clue the pale light from NGC 5609
had traveled for more than a billion years!
This fascinating quartet is located 3.8° south-southwest of
3.0-magnitude Gamma (γ) Boötes. I've observed NGC 5609
many times over the years, and in an 18-inch reflector it
appears as a tiny, circular spot (visible with direct vision)
with a brighter center. NGC 5614 (also known as Arp 178)
sports a tidal plume from a past interaction with a neighbor.
The Runner-Up
IC 2221 is the second most distant visual discovery in the
NGC/IC catalogs with a light-travel time of 1.18 billion years.
French astronomer Stéphane Javelle spotted it on the night of
February 28, 1900, using the 30-inch refractor at Nice Observatory
in southern France.
Although Javelle is little known today, his contributions
to the IC are incredible. He discovered 1,460 faint nebulae
between 1891 and 1903 using the large refractor. These finds
make him the third most prolific contributor to the entire
NGC/IC catalogs after William and John Herschel. Javelle
continued to explore the skies until 1911, adding another 400
discoveries that were never published.
IC 2221 lies in a desolate region in Lynx, 8.3° northeast of
1.6-magnitude Castor, or Alpha (α) Geminorum. I easily saw
the 15.2-magnitude galaxy with direct vision at 488× in my
48-inch and noticed a bright starlike nucleus. IC 2222, a more
prominent foreground galaxy, is only 2′ northeast. Although
Javelle's original position was accurate, some references incorrectly
list a completely different object here (PGC 22713).
NGC 5609
light-travel
time:
1.32 billion
years
NGC 5614
The Mighty Lion
The famous comet hunter Lewis Swift discovered the
15.2-magnitude elliptical galaxy IC 685 on April
11, 1888, with his 16-inch Clark refractor. Swift
was searching for new nebulae within the Lion's
hindquarters, formed by the three 2nd- and 3rdmagnitude
stars Beta (β) Leonis, or Denebola,
Delta (δ) Leonis, and Theta (θ) Leonis. IC 685
lies 1.3° to the east-southeast of the 10th- and
11th-magnitude galaxies NGC 3607 and NGC 3608,
which are fine targets for a small telescope.
Leo's distant denizen has a light-travel time of 1.14 billion
years. At 613×, I saw it using direct vision as a slightly
extended glow with a condensed nucleus.
Swift is notorious for positional errors when reporting new
NGC 5609
nebulae, and IC 685 is no exception. His published coordinates
and description leave room for doubt, and some sources
propose an alternate galaxy for IC 685. Both my sources (NED
and Steinicke) list this galaxy as Swift's IC 685.
NGC 3908 is another of Swift's finds in Leo, and this one
5′ × 3′
(28-inch, 408×)
20 DECEMBER 2023 * SKY & TELESCOPE
has a light-travel time of 1.11 billion years. He swept up the
15th-magnitude elliptical on April 10, 1885, but his reported
position is 7′ south of PGC 36967, the galaxy usually identified
as NGC 3908.
ALL SKETCHES BY HOWARD BANICH
Sky & Telescope - December 2023

Table of Contents for the Digital Edition of Sky & Telescope - December 2023
