ASTRONEWS
Webb to take
This meteorite’s
origin is mysterious on brown
dwarfs
VIEWING THE INVISIBLE. The April 2017 campaign to image the supermassive black hole in the heart
of the Milky Way is expected to release its results later this year.
Researchers at
the University of
Johannesburg recently
conducted a mineral analysis of the Hypatia
stone, an extraterrestrial rock fragment discov-
ered in Egypt in 1996. Their analysis found that
the stone’s mineral makeup is unlike any other
known object in our solar system.
The meteorite contains unusually high
amounts of carbon and low amounts of silicon,
a chemical composition opposite to that of
Earth, which has high amounts of silicon and
low amounts of carbon. Additionally, the grains
within Hypatia’s matrix (the stone inside which
dust grains are embedded) also have a unique
blend of phosphorus, nickel, and minute
amounts of iron. Because the ratio of elements
inside the grains differs from any other rocky
body in the solar system, researchers think the
grains were formed prior to the solar nebula
that birthed our planets.
Astronomers believe the solar nebula, a
massive cloud of dust and gas, produced the
Sun and the planets in our solar system. Planet
formation likely began as the nebula’s dust
began to clump together, a process long
believed to be homogenous. However,
Hypatia’s bizarre chemical composition and the
lack of silicate minerals in its matrix — which
are dominant in the compositions of Earth,
Venus, Mars, and most known meteorites —
cast doubt on this theory.
If Hypatia’s matrix is pre-solar, the question
of where it came from remains. And if it instead
formed from the same nebula that created the
planets, its never-before-seen makeup contra-
dicts the homogenous theory, leaving astrono-
mers to re-evaluate the distribution of
elements inside the nebula that formed our
solar system. — Amber Jorgenson
$350
20°
dwarfs in much finer detail
than current ground
instruments.
Webb’s ability to detect
atmospheric molecules will
not only assist in identifying
common compounds among
brown dwarfs, but also could
help pinpoint whether these
worlds hold the elements
needed to support life. — A.J.
Ecliptic in early June
Ecliptic in mid-August
July 3
15°
18 June 3
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May 4
Aug. 2
10°
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The upper cost of a
new earth science mission line
recommended to NASA by the
National Academies of Sciences,
Engineering, and Medicine.
constellation Perseus.
NGC 1333 is a hotbed for
brown dwarfs, including
those weighing only about 5
to 6 Jupiter masses. (They are
usually much larger, tens of
times more massive than
Jupiter.) Webb’s infrared
viewing capabilities will
enable Scholz to study these
rare, dim, low-mass brown
VENUS AT DUSK
5°
MILLION
TINY LIGHTS. NGC 1333 is just one of many targets planned for
the upcoming James Webb Space Telescope. The young star cluster
associated with this nebula contains numerous brown dwarfs; Webb’s
infrared capabilities will allow astronomers to study these hard-to-see
failed stars in greater detail. NASA/CXC/JPL
0°
OSSERVATORIO ASTROFISICO DI TORINO
Researchers have been try-
ing to unlock the mysteries
of brown dwarfs ever since
their existence was confirmed
in 1995. Observations of
these distant, dim objects
from Earth are limited, but
multiple researchers plan
to use NASA’s upcoming
James Webb Space Telescope
(JWST) to eliminate some of
the uncertainty surrounding
brown dwarfs. Plans to study
their atmospheres and gain
insight into their formation
are in the works, with the end
goal of better understanding
the dividing line between
stars and planets.
Researchers at the
Université de Montréal will use
JWST to study SIMP0136, a
brown dwarf with a cloudy
atmosphere. Brown dwarfs’
atmospheres are best viewed
in infrared light, but because
Earth’s atmosphere absorbs
this light, studying SIMP0136
from the ground has proven
difficult. Webb’s space-based
instruments will enable
researchers to study the
clouds’ chemical composition
without obstruction.
Aleks Scholz, an astrono-
mer at the University of
St. Andrews in Scotland, plans
to use Webb to study
NGC 1333, a nebula in the
ODD BEGINNING. The Hypatia
stone, discovered by geologist
Aly Barakat in 1996, contains a
combination of chemicals and
minerals that doesn’t match our
early solar system. MARIO DI MARTINO/INAF
April 4
March 5
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Azimuth West
THE “EVENING STAR.” Even at its dimmest, Venus shines nine times
brighter than the night sky’s brightest star, Sirius. But Venus stands out even
more when it lies far from the Sun. This chart plots the planet’s positions
for an observer at 40° north latitude an hour after sunset. Notice that Venus
reaches its peak altitude in late May and early June, more than two months
before its August 17 greatest elongation. That’s because the ecliptic — the
apparent path of the Sun and planets across our sky — makes a steeper
angle to the western horizon in springtime. — Richard Talcott
From 40° north
latitude, Venus
peaks at an
altitude of 16°
in early June.
FAST
FACT
W W W.ASTR ONOMY.COM
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