On the Nature of Stars

"`It's a star,' said the Professor of Astrology, `I think.'
`You think?'
The astrologer winced. They were standing in Unseen University's observatory, and the tiny ruby pinpoint on the horizon wasn't glaring at him any worse than his new master.
`Well, you see, the point is that we've always believed stars to be pretty much the same as our sun - '
`You mean balls of fire about a mile across?'
`Yes. But this new one is, well - big.'
`Bigger than the sun?' said Trymon. He'd always considered a mile-wide ball of fire quite impressive, although he disapproved of stars on principle. They made the sky look untidy.
`A lot bigger,' said the astrologer slowly.
`Bigger than Great A'Tuin's head, perhaps?'
The astrologer looked wretched.
`Bigger than Great A'Tuin and the Disc together,' he said. `We've checked,' he added hurriedly, `and we're quite sure.'
`That is big,' agreed Trymon. `The word "huge" comes to mind.'
`Massive,' agreed the astrologer hurriedly.
`Hmm.'
Trymon paced the broad mosaic floor of the observatory, which was inlaid with the signs of the Disc zodiac. There were sixty-four of them, from Wezen the Double-headed Kangaroo to Gahoolie, the Vase of Tulips (a constellation of great religious significance whose meaning, alas, was now lost).
He paused on the blue and gold tilework of Mubbo the Hyaena, and turned suddenly
`We're going to hit it?' he asked.
`I am afraid so, sir,' said the astrologer.
`Hmm.' Trymon walked a few paces forward, stroking his beard thoughtfully. He paused on the cusp of Okjock the Salesman and the Celestial Parsnip.
`I'm not an expert in these matters,' he said, `but I imagine this would not be a good thing?'
`No, sir.'
`Very hot, stars?'
The astrologer swallowed. `Yes, sir.'
`We'd be burned up?'
`Eventually. Of course, before that there would be discquakes, tidal waves, gravitational disruption and probably the atmosphere would be stripped away.'
`Ah. In a word, lack of decent organisation.'
The astrologer hesitated, and gave in. `You could say so, sir.'
`People would panic?'
`Fairly briefly, I'm afraid.'"

- Terry Pratchett, The Light Fantastic