NATIONAL SCIENCE DAY‘24, IUCAA - Mission Aditya L1
On National science day, February 28, 2024, the students of Fergusson College Pune came up with a demonstration on ISRO’s latest satellite, Aditya L1 and Sun.
Aditya L1 is India's first space based mission to study the Sun. The spacecraft is placed in the halo orbit around Lagrange point 1 (L1) of the Sun-Earth system, which is about 1.5 million km from the Earth. On June 2, 2024 Aditya-L1 spacecraft completed its first halo orbit around the Sun-Earth L1 point. Launched on September 2, 2023, it was inserted in its targeted halo orbit on January 6, 2024.
What is a Hola Orbit ?
A halo orbit is a periodic, three-dimensional orbit associated with one of the L1, L2 or L3 Lagrange points in the three-body problem of orbital mechanics.
What is Lagrange Point ?
Lagrange points are positions in space where objects sent there tend to stay put. At Lagrange points, the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them. These points in space can be used by spacecraft to reduce fuel consumption needed to remain in position.
Lagrange Points are positions in space where the gravitational forces of two body systems, like the Sun and the Earth produce enhanced regions of attraction and repulsion. These can be used by spacecraft to reduce fuel consumption needed to remain in position.
Aditya L1 Mission:-
Aditya L1 is placed at lagrange point L1 of the sun-earth system . A satellite around L1 has the major advantage of continuous viewing the sun without occultation / eclipses .
Aditya L1 science payloads: The instruments of Aditya-L1 are tuned to observe the solar atmosphere, mainly the chromosphere and corona. In-situ instruments will observe the local environment at L1. There are a total seven payloads on- board, with four of them carrying out remote sensing of the Sun and three of them carrying in-situ observation.
Payload includes
Visible Emission Line Coronagraph (VELC)
Solar Ultraviolet Imaging Telescope (SUIT)
High Energy L1 Orbiting X-ray Spectrometer (HEL1OS)
Solar Low Energy X-ray Spectrometer (SoLEXS).
Analyser Package For Aditya (PAPA)
Aditya Solar wind Particle Experiment (ASPEX)
Advanced Tri-axial High Resolution Digital Magnetometers
Major Science Objective
Study of Solar upper atmospheric (chromosphere and corona) dynamics.
Study of chromospheric and coronal heating, physics of the partially ionized plasma, initiation of the coronal mass ejections, and flares.
Observe the in-situ particle and plasma environments, providing data for the study of particle dynamics from the Sun.
Physics of solar corona and its heating mechanism.
Diagnostics of the coronal and coronal loop plasma: Temperature, velocity and density.
Development, dynamics and origin of CMEs.
Identify the sequence of processes that occur at multiple layers (chromosphere, base and extended corona) which eventually leads to solar eruptive events.
Magnetic field topology and magnetic field measurements in the solar corona.
Drivers for space weather (origin, composition, and dynamics of solar wind).
Inner structure of the Sun :-
This demonstration included the inner structure of the sun and surface phenomena like sunspots, as well as facts regarding the sun and its corona.
Sunspots are areas on the photosphere that have a lower temperature than the surrounding area due to increased magnetic flux. They often occur in the same region as solar flares or coronal mass ejections.
A corona is the outermost layer of a star's atmosphere. It consists of plasma. The Sun's corona lies above the chromosphere and extends millions of kilometers into outer space. It is most easily seen during a total solar eclipse, but it is also observable with a coronagraph.
The surface of the sun is called the photosphere, a term that means “sphere of light.” The glowing ball of light that you see in the sky is the photosphere. The surface of the sun is the only part that we can see from Earth on a typical day, without use of specialized equipment.
The chromosphere appears bright red because the hydrogen in the sun emits a reddish-colored light at high temperatures. The chromosphere is a thin layer of plasma that lies between the sun's visible surface (the photosphere) and the corona (the sun's upper atmosphere). It extends for at least 2,000 km .
The core is the innermost 10% of the sun's mass. It is where the energy from nuclear fusion is generated. Because of the enormous amount of gravity compression from all of the layers above it, the core is very hot and dense. Nuclear fusion requires extremely high temperatures and densities.
Solar Ultraviolet Imaging Telescope (SUIT):-
The Solar Ultraviolet Imaging Telescope (SUIT) instrument on board the Aditya-L1 spacecraft has successfully captured the first full-disk images of the Sun in the 200-400 nm wavelength range. SUIT captures images of the sun's photosphere and chromosphere in this wavelength range using various scientific filters.
On November 20, 2023, the SUIT payload was powered ON. Following a successful pre-commissioning phase, the telescope captured its first light science images on December 6, 2023. These unprecedented images, taken using eleven different filters , include the first-ever full-disk representations of the Sun in wavelengths ranging from 200 to 400 nm, excluding Ca II h. The full disk images of the Sun in the Ca II h wavelength has been studied from other observatories.
Among the notable features revealed are sunspots, plage, and quiet Sun regions, as marked in the Mg II h image, providing scientists with pioneering insights into the intricate details of the Sun's photosphere and chromosphere. SUIT observations will help scientists study the dynamic coupling of the magnetized solar atmosphere and assist them in placing tight constraints on the effects of solar radiation on Earth's climate
The development of SUIT involved a collaborative effort under the leadership of the Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune. This collaboration included ISRO, the Manipal Academy of Higher Education (MAHE), the Centre for Excellence in Space Science Indian (CESSI) at IISER-Kolkata, the Indian Institute of Astrophysics Bengaluru, the Udaipur Solar Observatory (USO-PRL), and Tezpur University Assam.
Imaging Modes:-
Synoptic Mode (default): Full disk (4k x 4k) : 11 science filters every 120 minutes. Full disk (2k x 2k) : Mg II h every minute
Region of interest (RoI):
8.2’ x 8.2’ Rol: Every 6s in 1 filters; Auto exposure adjustment automatic feature tracking.
Flare Mode: On board, auto detection of flares from SUIT, SoLEXS and HEL1OS. High cadence with auto Rol localization, gain and exposure adjustments.
Custom Mode: User proposed filters, exposure, Rol, cadence-within payload operational constraints.
SUIT Mg II k full sun images and Region of Interest(RoI) as seen through all narrow band filters
Conclusion:-
National Science Day 2024 at IUCAA highlighted the remarkable achievements of ISRO's Aditya L1 mission. This pioneering space-based mission, India's first dedicated to studying the Sun, successfully demonstrated advanced technology and scientific innovation. Positioned at the Lagrange point 1 (L1) of the Sun-Earth system, Aditya L1 provides continuous, unobstructed views of the Sun, offering valuable insights into solar dynamics, the solar atmosphere, and space weather phenomena.
Key payloads, such as the Solar Ultraviolet Imaging Telescope (SUIT), have already yielded unprecedented full-disk images of the Sun, enhancing our understanding of the Sun's photosphere and chromosphere. The mission's success is a testament to the collaborative efforts of multiple Indian scientific institutions and underscores India's growing capabilities in space research. As Aditya L1 continues to observe and gather data, it promises to significantly advance our knowledge of solar physics and its impact on space weather, contributing to global scientific endeavors.
