EI2GYB > ASTRO 26.10.25 12:45z 173 Lines 10425 Bytes #197 (0) @ WW
BID : 46944_EI2GYB
Read: GUEST
Subj: 4MOST telescope facility captures first light
Path: ED1ZAC<ED1ZAC<LU4ECL<UA6ADV<I0OJJ<IR0AAB<VE3CGR<VE2PKT<PY2BIL<EI2GYB
Sent: 251026/1220Z @:EI2GYB.DGL.IRL.EURO #:46944 LinBPQ6.0.25
#####
_ _ _ _ #### _\_
/ \ ___| |_ _ __ ___ | \ | | _____ _____ ##=-[.].]
/ _ \ / __| __| '__/ _ \ | \| |/ _ \ \ /\ / / __| #( _\
/ ___ \\__ \ |_| | | (_) | | |\ | __/\ V V /\__ \ # \__|
/_/ \_\___/\__|_| \___/ |_| \_|\___| \_/\_/ |___/ \___/
.' `.
+------------------------------------------------------------------------------+
4MOST telescope facility captures first light
On October 18, 2025, the 4-meter Multi-Object Spectroscopic Telescope (4MOST)
facility, installed on the VISTA telescope at the European Southern
Observatory's (ESO) Paranal Observatory in Chile, obtained its first light.
This milestone is a crucial step in the life of any telescope, marking the
moment it is ready to begin its scientific journey.
Moreover, 4MOST does not simply take images of the sky; it records spectra,
capturing the light of each object in every individual color. With this
capability, it can unravel the light of 2,400 celestial objects simultaneously
into 18,000 color components, allowing astronomers to study their detailed
chemical composition and properties.
Once fully operational, 4MOST will investigate the formation and evolution
processes of stars and planets, the Milky Way and other galaxies, black holes
and other exotic objects, and of the universe as a whole. By analyzing the
detailed rainbow-like colors of thousands of objects every 10-20 minutes, 4MOST
will build a catalogue of temperatures, chemical compositions, velocities and
many more physical parameters of tens of millions of objects spread across the
entire Southern sky.
4MOST is the largest multi-object spectroscopic survey facility in the southern
hemisphere and is unique in its combination of large field of view, number of
simultaneous observed objects, and number of spectral colors simultaneously
registered. Development started in 2010 and the facility has been designed to
operate for at least the next 15 years.
The Leibniz-Institut für Astrophysik Potsdam (AIP) is the lead institute of the
4MOST Consortium that has built and will scientifically operate the facility.
Next to overall management, AIP has been involved in many aspects of the
facility, like its wide field camera with six lenses up to 90 cm in diameter,
its guiding and focusing system, and its fiber system that contains more than
2,400 glass fibers, each with a diameter of a human hair. AIP is also strongly
involved in determining 4MOST's operations scheme, including observing planning
and data archiving.
4MOST Principal Investigator Roelof de Jong, Milky Way section head at AIP,
remarks, "It is incredible to see the first spectra from our new instrument.
The data looks fantastic from the start and bodes well for all the different
science projects we want to execute. That we can catch the light that has
sometimes traveled for billions of light years into a glass fiber the size of a
hair is mindboggling. An outstanding feat only made possible by an amazing
development team. Can't wait till having the system operating every night."
4MOST Project Manager Joar Brynnel adds, "Reaching this milestone is a
wonderful achievement after more than a decade of intensive efforts. It is hard
to put in words the excitement of realizing that the facility not only meets,
but even exceeds the required performance. It has been a true privilege to
manage this huge consortium for over a decade. Without the commitment by all
team members and institutions involved, which has genuinely been beyond
expectations, we would not have been able to deliver 4MOST to the VISTA
telescope in such good shape. I am really looking forward to the exciting
results from 4MOST over the years to come."
"With the First Light of 4MOST, we are opening a new chapter in sky surveys.
Its 2,436 optical fibers allow us to capture thousands of objects in the
southern sky simultaneously. 4MOST will help to answer fundamental questions
about the formation of the Milky Way, the evolution of galaxies and the forces
that shape the universe," says Prof. Dr. Matthias Steinmetz, Scientific
Director of the Leibniz Institute for Astrophysics Potsdam (AIP).
The First Light observations exemplify the unique capabilities of 4MOST: its
ability to observe a very large field of view and its capability to investigate
a large number of very different objects and science cases simultaneously in
great detail. One of the objects dominating the First Light observation of
4MOST is the elongated galaxy NGC 253, also called the Sculptor or Silver Coin
galaxy.
Except for the Magellanic Clouds, it is the galaxy with the largest apparent
diameter in the southern sky, with nearly the same diameter as the moon, only
much fainter. It was discovered by Caroline Herschel in 1783, is at a distance
of about 11.5 million light years, and is known to currently form a lot of new
stars. The 4MOST observations also capture a super star cluster, various hot
and cold stars and their movements, and gas glowing from newly formed stars in
this galaxy.
The other large object seen in the field is the Globular Cluster NGC 288, a
very dense group of about 100,000 very old stars on the outskirts of the Milky
Way at a distance of about thirty thousand light years. It formed about 13.5
billion years ago in the very earliest phases of the formation of the Milky
Way. Its stars contain very small amounts of most chemical elements heavier
than hydrogen and helium, reflecting its pristine composition.
Next to these two very large objects, 4MOST obtained spectra of more than two
thousand other objects in its first science observation of just 20 minutes.
These include spectra of a large variety of bright and faint stars in our Milky
Way, allowing scientists to determine their temperature, mass, diameter,
velocity, age and evolutionary stage, and chemical composition.
Beyond the Milky Way, spectra of a pair of overlapping galaxies at 900 million
light years were obtained, as well as spectra of more than a thousand other
galaxies near and far-up to 10 billion light years-to determine their distance,
internal velocity, and star formation history or the mass of their central
black hole.
The 4MOST science team consists of more than 700 investigators from
universities and research institutes around the world. In its first five years
of operations, 4MOST will conduct 25 different science programs, ten designed
by institute members of the consortium that built the instrument, whereas the
other fifteen programs were selected by an external committee of astronomers
nominated by ESO. Uniquely, the multi-fiber nature of 4MOST enables many
science programs to be observed simultaneously.
For example, a few fibers can be used to study rare objects, while at the same
time, another program can use most other fibers to make large statistical
samples of stars or galaxies. Highlighted 4MOST science cases are the origin of
the chemical elements and the formation of the first stars, the growth of the
Milky Way over cosmic time, the formation and evolution of galaxies and black
holes, the make-up of the unseen dark matter that seems to encompasses most of
the mass in galaxies, and the nature of dark energy that drives the
accelerating expansion of the universe.
At the heart of the system, 4MOST uses 2,436 optical fibers, each the size of a
human hair, to catch the light of celestial objects. Light from each of these
fibers is transported to the spectrographs that break up the light into its
different colors. A large, new, nearly 1m-diameter optical camera lens system
was installed in the VISTA telescope of the European Southern Observatory (ESO)
in Chile to give 4MOST a field of view on the sky of 2.5 degrees diameter, five
times larger than the diameter of the moon and one of the largest in the world
for a 4m-class telescope.
4MOST will observe a new set of objects in the sky every 10-20 minutes, using a
fiber positioner that moves all fibers to observe new objects in less than two
minutes. The fibers transport the light to three spectrographs that each
observe 800 objects simultaneously, where their light is first broken up into
red, green, and blue components and then in further detail to then be
registered by large 36 megapixel detectors. There are two spectrographs that
cover the entire color spectrum from the very blue all the way into the
infrared (370-950 nm), whereas a third spectrograph looks at higher wavelength
resolution in three selected color bands to better measure chemical element
abundances in stars.
Planning of 4MOST observations is done remotely from the Max Planck Institute
for Extraterrestrial Physics (MPE) in Garching near Munich. A few minutes
before the next observation needs to start, the next field and objects are
optimally selected based on the latest weather and observing conditions.
Executing the observations and maintaining the instrument is the responsibility
of the European Southern Observatory (ESO). The data obtained are transferred
to the 4MOST data center at the University of Cambridge, where they are
analyzed with an extensive set of software pipelines to extract physical
parameters of the studied objects. The analysis results are then transferred to
data archives at the Leibniz Institute for Astrophysics Potsdam (AIP) and ESO
to be distributed to all project members and to the entire scientific community
for scientific exploration.
+------------------------------------------------------------------------------+
================================================================================
= ____ __ ____ ___ _ _ ____ ____ ____ ____ =
= ( __)( )(___ \ / __)( \/ )( _ \ ( _ \( _ \/ ___) =
= ) _) )( / __/( (_ \ ) / ) _ ( ) _ ( ) _ (\___ \ =
= (____)(__)(____) \___/(__/ (____/ (____/(____/(____/ =
= Serving The Irish Packet Radio Network Since 2006 =
= Packet: EI2GYB@EI2GYB.DGL.IRL.EURO / EI2GYB@WINLINK.ORG =
= Email/PayPal: EI2GYB@GMAIL.COM =
================================================================================
Read previous mail | Read next mail