Khám Phá Thang Độ Sáng Sao Từng Bước
freetoolonline.com editorial team
The Stellar Magnitude Scale Explorer answers one question as soon as the page loads: how much brighter is one star than another. Drag to orbit, scroll to zoom, and toggle Apparent vs Absolute mag to read the Pogson brightness rail directly, with no star catalog and no photometric pipeline involved. Everything renders on your own device - 0 MB installed, USD 0, no account, no server rendering.
Step 1 - apparent mode
Start in Apparent mag so Sun, Sirius, Vega, and the naked-eye limit size from Earth-sky magnitudes. Keep the facts panel open to read each value as you compare the spheres.
Step 2 - absolute mode
Press Absolute mag and watch the Sun shrink to its about +4.83 absolute rank at 10 pc. That jump between the two modes is the clearest single moment in a five-minute classroom demo: the brightest object on the apparent rail becomes an ordinary star once every object sits at the same distance.
Step 3 - focus buttons
Press Sun, Sirius, Vega, and Naked-eye limit, then fullscreen to keep controls visible while you compare soft flux sizes.
Stellar magnitude reference values
| Reference | Value | Mode |
|---|---|---|
| Sun apparent magnitude | ~-26.74 | Apparent rail |
| Sirius apparent magnitude | ~-1.46 | Apparent rail |
| Vega apparent magnitude | ~0.03 | Apparent rail |
| Naked-eye limit | ~+6 | Apparent rail |
| Pogson flux step | ~2.512x per mag (5 mag = 100x) | Scale math |
| Sun absolute magnitude | ~+4.83 | Absolute mode |
Sessions this explorer does not fit
The Stellar Magnitude Scale Explorer is a teaching rail, not a measurement tool. It is not a Hipparcos or Gaia catalog map, it does not report measured angular diameters, and it is not photometric reduction software - the sphere sizes are a display scale, not real angular sizes. For stages from nebula to remnant use the Star Lifecycle 3D Explorer; for galactic structure use the Milky Way Map 3D Explorer; for distance measurement use the Parallax Distance 3D Explorer. Next to a textbook that prints one static magnitude list, this explorer adds the Apparent vs Absolute toggle and sized spheres in a browser-only 3D view.