Sky & Telescope - December 2023 - 19

JIMI LOWREY / STEPHEN ODEWAHN / MCDONALD OBSERVATORY /
ANN ISAACS (UNIVERSITY OF MINNESOTA)
Corrected (subtracted) flux
As a dedicated visual observer, I was interested in these distant
galaxies - I established which were the 12 farthest found
by these observing pioneers and proceeded to observe them.
Let's tour these Distant Dozen - eight are targets in the spring
sky and four in the autumn sky. We'll start with the galaxy
with the highest redshift and work our way in. Throughout
my research on the 94 " far out " galaxies, I've relied on the
NASA Extragalactic Database (NED) and Wolfgang Steinicke's
revised NGC/IC catalog (https://is.gd/steinicke_ngcic)
as the primary references for identification and data.
Unless stated otherwise, I observed these objects
with my 48-inch f/4.0 reflector.
The Strange Case of NGC 1262
If you google " most distant object in the NGC "
one hit will be NGC 1262, a low-surface-brightness,
barred spiral galaxy in Eridanus. American
astronomer Francis Leavenworth discovered it with
the 26-inch Clark refractor at the University of Virginia on
November 12, 1885. Its claim to fame is a reported redshift
of z = 0.116, implying a light-travel time of 1.5 billion years.
The light of NGC 1262 spreads out over nearly 1′, which
So, I devised a plan to address our doubts: Request time on a
professional telescope to pin down the redshift of NGC 1262.
NGC 1262
light-travel
time:
686 million
years
Telescope Time
I talked to my friend Stephen Odewahn, a resident astronomer
at McDonald Observatory in West Texas (see S&T: Feb. 2021,
p. 36), about measuring the redshift of NGC 1262 to solve
this mystery. He said he'd happily assist me with the project
- we needed to secure observing time on the 107inch
Harlan J. Smith Telescope using the Virus-P
spectrograph. This is the prototype of the fiber-fed
spectrographs for the Dark Energy Experiment
conducted using the Hobby-Eberly Telescope (the
11-meter telescope at the McDonald site). Yes! I
now had help from a professional astronomer.
The next step was applying in person with the
head of the telescope-time allocation committee,
Anita Cochran. She supported the project but warned
me the spectrograph was only available during two periods
translates to a physical diameter of more than 400,000 lightyears
at that distance, making it a gargantuan spiral. (For
comparison, the Milky Way is 100,000 light-years across.)
But Steve and I often discussed our doubts about NGC 1262's
redshift. In addition to its unusually large diameter, the
photographic detail on an image taken by PanSTARRS (one
of two 1.8-meter telescopes atop Haleakala¯ on the island of
Maui) suggested it was much closer. I've viewed hundreds of
galaxies at a billion light-years, and most appear in the eyepiece
(and on sky survey images) as just small, faint fuzzies.
NGC 1262 Spectrum
Rest
0.0
0.1
0.2
0.3
0.4
0.5
0.6
3800
Feature
O II
O II
G-band
Hδ
Ca II H
H9 Ca II K
4000
4200
4400
4600
Wavelength (angstroms)
4800
5000
WRITTEN IN THE LINES This spectrum of
NGC 1262 dislodged the galaxy as the most
distant object in either the NGC or the IC that can
be visually observed. Until the author's requested
observations, sources placed NGC 1262 at a distance
of 1.5 billion light-years. These data placed it
much closer, at almost 700 million light-years.
Ca II K
Ca II H
H9
Hδ
G-Band
Wavelength
3727.000
3934.000
3968.000
3835.390
4101.740
4305.000
Observed
Wavelength
3915.220
4134.272
4168.430
4027.730
4309.955
4523.596
that would coincide with when NGC 1262 was well-placed in
the sky. She contacted the astronomers who had been allocated
telescope time then (through competitive proposal submissions).
Both teams agreed to collect the data for me during
their runs. Excellent news! Now we just needed a clear night.
First on the schedule in late August were Midge Hartshorn
and Jason Young of Mt. Holyoke College (Massachusetts).
Unfortunately, it rained nearly every day and was mostly
cloudy at night, and when it was clear the telescope experienced
mechanical problems. Their run was a total washout.
Now I had only one more chance to collect the data.
Next up, in November, was Ann Isaacs of the University
of Minnesota. We had our fingers crossed that her run would
sk yand tele scope .o r g * DECEMBER 2023 19
https://www.is.gd/steinicke_ngcic https://skyandtelescope.org/
Sky & Telescope - December 2023

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