OVERVIEW
] STARThe Sun is a G2V yellow main-sequence star, 1.000 from Earth, shining at apparent magnitude −26.74 (). It has a mass of 1.00 and a mean radius of 1.00 · 695 700 . Other catalogues list it as Sol. It has been known since antiquity.
Our star. A middle-aged yellow dwarf fusing 600 million tonnes of hydrogen every second, 4.6 billion years into a 10-billion-year life.
- WHAT IT IS
- Yellow main-sequence star
- HOW FAR
- 1.000
- HOW BIG
- 1.00 · 695 700
- HOW BRIGHT (V)
Its mean radius: half the width across.
Bright enough for the naked eye, under a sky dark enough.
THE MODEL
] CATALOGUED RADIUSCALCULATED · NOT AN OBSERVATION · CATALOGUED RADIUS · MEASURED TEMPERATURE · 5770 K · MEASURED RADIUS · SPOTS OVER 0.20% OF IT · WITH A CORONA
Drawn from the catalogued radius and from the same properties the picture at the top of this page uses, at the distance a flight to it would stop. It is cool enough to convect at the surface, so it has a magnetic field wound by that convection, and the field is what everything else here comes from: the dark patches are places where it is strong enough to stop the heat arriving, so they are cooler rather than merely darker, and they are drawn at the fraction of the surface a star this active is measured to cover. The bright web between them is the same field swept to the edges of the larger convection cells, and the brighter patches beside the spots are that web bundled up — both of them brighter towards the limb, because what makes them bright is seeing down the wall of a magnetic tube rather than into its mouth. The fringe standing off the edge is the chromosphere, a forest of jets a few hundred kilometres wide, and the flames leaning out of it are prominences: chromospheric gas held up by the field, drawn at the height one reaches and the width one has. A flare is a second, far hotter thing radiating on top of the photosphere rather than the photosphere brightening, which is why the same flare is barely visible on a hot star and doubles a cool one. The streamers reaching out past the limb are the corona, which is a millionth of the disc's brightness and drawn far brighter than that, since at its own contrast nothing short of hiding the disc reveals it. Drag it, or use the arrow keys, to look from another direction. The stars behind are the 498,631 this catalogue holds real distances for, at their real positions and drawn from where the camera actually is — so the constellations are wrong, and that is the point. This is the sky from there, not the sky from here.
IMAGES
] 4 FRAMES- Matúš Motlo
CC BY-SA 4.0 - NSO/AURA/NSF
CC BY 4.0 - Burkhard Mücke
CC BY-SA 4.0 - W.carter
CC BY-SA 4.0
OBSERVING
] FROM WHERE YOU AREWhat it takes to see Sun for yourself. Everything in this part of the page is worked out for a real horizon, a real night and the equipment you say you have.
Say where you are, and this line says when Sun is worth going out for.
THROUGH AN EYEPIECE
] 150 MM TELESCOPE · 25 MM EYEPIECENever point any of this at the Sun. An eyepiece concentrates everything the lens or mirror gathers, and a moment of it will take your sight permanently. A certified solar filter, over the front of the instrument and never at the eye end, or a pinhole projection onto paper. Today it is 31.8′ across. It is a disc to your eyes alone, and at 48× behind a filter it is big enough to look around inside.
- 48×
- 1.08
- 1.25
- 13.0
- 31.8
- SHOWS A DISC FROM
- no at all
- MAGNITUDE TODAY
- −26.74 · within reach
Computed for 2026-09-11 from the centre of the Earth, and from the mean radius the catalogue holds. A distance changes daily, so this width is a fact about that date and not about the body.
SPECTRUM
] A SPECTRUM OF ITS TYPENo survey in this catalogue has measured the Sun’s own spectrum: the one that reaches deepest saturates on the brightest stars, and no spectrograph has been pointed at the whole sky. What is drawn below is the average of several real stars of the same class, G2 V. It shows what a star like this one shows, and every line named on it is a line of the type rather than a measurement of the Sun.
A star gives out light at every wavelength at once. The dark gaps are atoms in the thin gas above its surface, each one removing the single colour it is able to absorb — which is how a list of ingredients is read off something nobody will ever touch.
Point at a labelled line — or an element above — to see which atom makes it and where it falls.
- HEAVY ELEMENTS The catalogued iron figure for the Sun is +0.01, which puts it at about the Sun's share of the elements heavier than helium. The figure is a logarithm: nought is the Sun, and every whole step is a factor of ten. It comes from published measurements of the star itself, not from the spectrum above — which belongs to the type.
Pickles (1998) stellar spectral flux library. G2 V — the average of several real stars of this type, not an observation of any one star. Sampled every 5 angstroms; 1,895 points rebinned onto 1,024 log-spaced display points and normalised to the median flux. Brightness is scaled to this spectrum’s own middle value, so the shape is the measurement and the height is not. The 10 lines named above are the ones that stand clear of the scatter and of the features around them; a spectrum at this sampling holds many more that it cannot separate. The samples themselves, as JSON, CSV or VOTable.
LIFE OF THIS STAR
] STAGE 2 OF 5The Sun is a yellow star on the main sequence, fusing hydrogen in its core; in about five billion years it will swell into a red giant, and end as a white dwarf.
- COLLAPSING CLOUDtook about fifty million years
- MAIN SEQUENCEabout five billion years leftNOW
- RED GIANTabout a billion years of it, when it comes
- PLANETARY NEBULAgone in about twenty thousand years
- WHITE DWARFcooling from then on
NOW Hydrogen fuses to helium in the core, and the outward push of that exactly balances the star's own weight. This is the long, steady stretch — nine-tenths of a star's life — and it ends when the core's hydrogen is gone.
NEXT With the core out of hydrogen, the star swells enormously and its surface cools to red. It burns helium in the core and hydrogen in a shell around it, and it loses mass from its surface the whole time.
EVERY STAGE ON THIS TRACK
- COLLAPSING CLOUDtook about fifty million years
- A cold clump of gas and dust falls in on itself and heats as it falls. It stops being a cloud and starts being a star at the moment its core is hot enough to fuse hydrogen.
- MAIN SEQUENCEabout five billion years leftNOW
- Hydrogen fuses to helium in the core, and the outward push of that exactly balances the star's own weight. This is the long, steady stretch — nine-tenths of a star's life — and it ends when the core's hydrogen is gone.
- RED GIANTabout a billion years of it, when it comes
- With the core out of hydrogen, the star swells enormously and its surface cools to red. It burns helium in the core and hydrogen in a shell around it, and it loses mass from its surface the whole time.
- PLANETARY NEBULAgone in about twenty thousand years
- The outer layers drift away and the exposed core lights them from inside. It is one of the shortest things a star does and one of the most visible — most of the glowing shells in this catalogue are this stage of some star.
- WHITE DWARFcooling from then on
- The bare core, about the size of the Earth, held up by nothing but the resistance of its own crushed electrons. No fusion, no fuel, nothing left to do but cool.
- HOW FIRM No mass has been measured for this star. The figure above is inferred from its temperature by way of the main-sequence relation between the two, which is tight enough to be worth stating and is still an inference.
Which stage the Sun is in was read from its catalogued class, its temperature and its total output at every wavelength — not from its brightness in visible light alone, which understates a cool star by a factor of several. The mass it started with is about the Sun's own mass, from its temperature, and that mass is what chooses the track. Every span of time here comes from the standard relation between a star’s mass and how long its fuel lasts, rounded to a single figure. They are orders of magnitude and none of them is a date.
CATALOG DATA
] 10 FIELDSThe raw catalogue values, as the source published them, with the error bars where one was published — sorted by what each set of figures is about rather than by the order they happened to be stored in.
WHAT KIND OF THING IT IS
What the object is in itself, rather than how it happens to look from here.
- Spectral type
- Surface temperature
- 5772
- Surface gravity (log g)
- Metallicity ([Fe/H])
- Age
- 4.6×10⁹
- Rotation period
- 25.4
WHERE IT IS AND HOW IT MOVES
Position, motion across the sky and the size it covers on it. These are measurements of the object as seen from here, so every one of them depends on where here is.
- North pole (RA)
- 286.13
- North pole (Dec)
- 63.87
WHERE THESE FIGURES CAME FROM
Which catalogue, paper or model each of the fields above was read from, where the source named one.
- Stellar parameters from
- Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)
- Metallicity from
- One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)
ALSO KNOWN AS
] 2 DESIGNATIONS- Common name Sol
- Common name Sun
CITE THIS PAGE
] DR1This page is live and its numbers move when an upstream refreshes, so the citation names the release the rows belong to rather than the day you read them. The release itself is frozen, republished as a bundle, and is what a data-availability statement should point at.
SpaceCatalog. Sun [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/sun
@misc{spacecatalog_sun,
author = {{SpaceCatalog}},
title = {{Sun}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/sun},
note = {Catalogue entry, data release DR1 (2026-08-21). Values from SpaceCatalog curated data.}
}The values above were taken from SpaceCatalog curated data — CC-BY-4.0. Citing this page does not replace citing that catalogue.
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