Sky & Telescope - September 2023 - 9

Analysis of the system's brightness at
different wavelengths had also suggested
the presence of a dusty inner disk
analogous to the main asteroid belt.
Now, the new JWST images reveal
unprecedented details. In the inner
system the telescope imaged the
asteroid-belt analog. There's also a new
belt inside the previously known one
(labeled " inner belt " in the figure at
left) and a new " inner gap. "
" My first thought was: 'Wow!', "
remarks Samantha Lawler (University of
Regina, Canada), who wasn't involved
in the study.
The inner dusty disk that the
researchers imaged is like the asteroid
belt in our own solar system in terms
of the heat it emits; however, it's more
extended than previously thought, from
at least 10 astronomical units (a.u.)
out to as far as 96 a.u. The gap and the
inner belt that lie beyond this disk are
both new discoveries.
Interestingly, the inner belt is misaligned
with the outer, Kuiper Belt-like
nature of dark matter is settled, " he
says. According to team member George
Smoot (Donostia International Physics
Center, Spain), the James Webb Space
Telescope should discover many more
gravitationally lensed systems, offering
a more stringent test of the idea.
RX J0911+0551
analog. An unseen exoplanet might
have carved out the disk-belt gap, much
as Jupiter's gravitational effects shape
our asteroid belt. Modeling is underway
to investigate the potential planet.
The JWST images also revealed a feature
that the team initially termed the
" Great Dust Cloud, " thinking it might
have been formed by a planet-scale
collision. But a later look through the
archives of the Atacama Large Millimeter/submillimeter
Array and the Keck
Observatory show emission from the
same position between 6 and 18 years
prior to the JWST observations. Since
any part of the system would move with
Fomalhaut across the sky, the archival
images indicate that the source is
instead in the background. Grant Kennedy
(University of Warwick, UK) and
colleagues posted this conclusion on the
arXiv preprint server on May 17th.
Nevertheless, the JWST images have
revealed a dynamic system, which will
surely divulge more details in time.
¢KIT GILCHRIST
If that future work cements the
study's conclusions, Hardy says it would
be a spectacular discovery. " There would
be major implications, " he says, " not
just for astrophysics but also for highenergy
fundamental particle physics. "
¢COLIN STUART
WGD J0405-3308
HS 0810+2554
IN BRIEF
Meteorite Crashed into
New Jersey Home
When Suzy Kop stepped into her father's
bedroom on May 8th, she saw a black,
mango-size rock on the floor, its broken
surface exposing a creamy interior. Looking
around, she spotted two holes in the
ceiling, and she knew something wasn't
right. Some 15 minutes before Kop had
arrived (around 12:30 p.m.), there was a
report of a fireball in the area. As it happened,
the heavy end of that falling star
crashed through the roof of the home in
Hopewell Township, New Jersey. The meteorite
struck the floor with such force that
it rebounded and punched a second hole
in the ceiling before landing back on the
floor. Unsure what to do, Kop called the
Hopewell police for assistance. A hazmat
team arrived to examine the cosmic
trespasser for signs of radioactivity, though
meteorites are no more radioactive than a
banana. Meanwhile, the police contacted
Shannon Graham (College of New Jersey);
she and colleagues confirmed the rock's
cosmic origin based on visual inspection,
density measurements, and examination
with an electron microscope. A first analysis
indicates it's likely an LL-6 chondrite, a
stony meteorite with low iron content.
¢BOB KING
Magnets Bad for
Meteorites
PS J1606-2333
WFI 2033-4723
SDSS J1330+1810
pEach of these snapshots shows multiple, distorted images of a background quasar, its light
bent by a massive foreground galaxy. The system under study, HS 0810+2554, is the one at upper
right with a Mickey Mouse shape.
Amateurs often use cheap but powerful
magnets to quickly identify iron-rich
meteorites. But in doing so, they can erase
meteorites' original magnetic fields. In
the April Journal of Geophysical Research:
Planets, Foteini Vervelidou (MIT)
and colleagues show that using standard
magnets on terrestrial basalt - a common
analog for stony meteorites - resets
the material's magnetism. " Over the last
few decades, we have discovered that
meteorites contain unique magnetic records
that tell us how planets formed and
evolved, " says team member Benjamin
Weiss (also at MIT). " However, even just
briefly touching a fist-sized meteorite with
a magnet essentially obliterates this record
forever. " Instead of magnets, Vervelidou
and colleagues advocate using low-field
susceptibility meters, which won't disturb
the sample's original magnetism. However,
these instruments are expensive, and
visual inspection can also go a long way
toward identifying samples.
¢DAVID DICKINSON
skyandtelescope.org * SEPTEMBER 2023
9
NASA / ESA / A. NIERENBERG / T. TREU

http://skyandtelescope.org

Sky & Telescope - September 2023

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