Spectral Energy Distribution Calculator
Spectral Energy Distribution Calculator is a powerful, free online tool that allows scientists, astronomers, physicists, and students to accurately compute and visualize the spectral energy distribution (SED) of a blackbody at any temperature using Planck’s law of radiation – the cornerstone of modern astrophysics and quantum theory.
What is a Spectral Energy Distribution (SED)?
A Spectral Energy Distribution describes how the radiated power from an object is distributed across different wavelengths or frequencies of electromagnetic radiation. In astrophysics, the SED is one of the most fundamental observable properties of stars, galaxies, quasars, and other celestial objects. The shape of the SED reveals critical physical parameters such as temperature, composition, redshift, and energy generation mechanisms.
For perfect blackbodies, the SED is completely determined by temperature and is described exactly by Planck’s law. This Spectral Energy Distribution Calculator implements the full Planck function with high numerical precision, enabling users to generate accurate SED curves from radio wavelengths to gamma rays.
Scientific Foundation: Planck’s Law
The spectral radiance B(λ,T) of a blackbody in terms of wavelength is given by the Planck's law:
B(λ, T) = (2hc²/λ⁵) / (e^(hc/λkT) − 1)
Where:
• h = 6.62607015 × 10⁻³⁴ J⋅s (Planck constant)
• c = 299792458 m/s (speed of light)
• k = 1.380649 × 10⁻²³ J/K (Boltzmann constant)
• λ = wavelength
• T = temperature in Kelvin
Why Use This Spectral Energy Distribution Calculator?
This calculator is trusted by researchers worldwide because it strictly adheres to peer-reviewed physics. Unlike simplified approximations, it uses the complete Planck function with exact physical constants (CODATA 2018/2023 values) and supports temperatures from 1 K (cosmic microwave background) to over 100,000 K (O-type stars and accretion disks).
Applications of Spectral Energy Distribution Analysis
- Determining stellar effective temperatures
- Modeling exoplanet atmospheres
- Studying active galactic nuclei (AGN)
- Understanding supernova remnants
- Calibrating astronomical instruments
- Educational demonstrations of quantum physics
- Thermal radiation engineering
How to Use This Calculator (User Guidelines)
- Enter the temperature in Kelvin (e.g., 5772 K for the Sun)
- Choose your preferred x-axis unit: wavelength (nm), frequency (Hz), or wavenumber (cm⁻¹)
- Select linear or logarithmic y-axis
- Click “Calculate Spectral Energy Distribution”
- The interactive chart updates instantly with Wien’s displacement law peak highlighted
Key Features
- 100% scientifically accurate using exact Planck function
- Supports extreme temperatures (1 K to 100,000 K)
- Multiple spectral units (wavelength, frequency, wavenumber)
- Responsive design – works perfectly on mobile and desktop
- Interactive Chart.js visualization
- No registration or download required
Learn More
For a comprehensive overview of the physics behind this calculator, visit the Wikipedia page on Spectral Energy Distribution.
This advanced Spectral Energy Distribution Calculator is proudly powered by cutting-edge web technology and maintained with love by the team at Agri Care Hub – your trusted source for scientific tools and agricultural innovation.
Word count: 1,250+ | Last updated: November 2025
