Kepler is the remnant of the last supernova in the Milky Way seen with the naked eye, a new star in Ophiuchus studied by Johannes Kepler himself.
At a glance
| type | supernova remnant |
|---|---|
| distance from the Sun | 16,300 light-years (5 kpc) |
| its light left it | 16,300 years ago |
| size in the piece | about 14 light-years acrossmodel |
Read off the piece’s own catalogue, the same values it draws with. Model marks a property of the piece’s galaxy model rather than a measurement.
About Kepler (SN 1604)
A new star, SN 1604, flared in Ophiuchus, close on the sky to Jupiter, Mars and Saturn, and was followed for many months by Johannes Kepler, who wrote a book about it. Like Tycho’s star before it, it showed that the sky beyond the planets could change. No supernova in our Galaxy has since been seen by eye.
The remnant is a shell of hot gas bright in X-rays and radio, lying well above the plane of the Galaxy. Its X-ray spectrum, rich in iron, points to a thermonuclear explosion of a white dwarf, but the shell is ploughing into dense material on one side, as if the system had shed gas before it exploded, which is unusual for that kind of supernova.
What you see in the piece
It is drawn as a hollow shell of shocked gas, faint at its distance in visible light; the radio band, where supernova shells shine, shows it more clearly.
Measured or modelled
Its distance is uncertain, and the nature of the star system that exploded is debated. The drawn extent is modelled.
Questions
What was Kepler’s supernova?
It was a supernova in Ophiuchus followed by Johannes Kepler, and it remains the last supernova in the Milky Way seen with the naked eye.
How far away is Kepler’s supernova remnant?
The Kepler remnant is about 16,300 light-years (5 kpc) from the Sun, though its distance is uncertain.