Donati's comet

Donati's comet

(doh-mah -teez) (1858 VI) A spectacular comet famous for its coma with multiple haloes: parabolic envelopes with vertices toward the Sun and foci near the apparent nucleus. These haloes were regular and sharp and are thought to have been produced by repetitive ejection of material from a single active area exposed successively to solar radiation as the solid cometary nucleus rotated every 4.6 hours.

Donati’s Comet

 

a long-period comet having a period of about 150 years. One of the brightest comets, it moves around the sun in an elongated elliptical orbit having a perihelion of 0.58 astronomical units and an aphelion of 300 astronomical units. The comet was discovered on June 2, 1858, by Giovanni Donati. The remarkable duration of its visibility to the naked eye (from the middle of August to the beginning of December) has made it possible to study it in great detail. In the first half of October 1858, Donati’s comet attained a brightness of a star of zero magnitude and had three tails: tails of types I and II (following F. A. Bredikhin’s classification) measuring up to 70 million km long and a short, diffuse, type III tail. Up to seven luminous envelopes have been observed around the nucleus.

References in periodicals archive ?
(Donati's Comet was seen in the sky in October 1858) and then when tired of us, you should go off to see dear Penrice and show its manifold charms to your wife and daughters!" Mr Morris said: "Emma was a great help to her husband and was certainly a character, describing herself in one letter to a relative as 'your cantankerous aunt'."
(4) Moreover, changes to the nature of its head and the tail added significantly to our knowledge of cometary behaviour, building on the picture assembled through the spectacles presented earlier by Donati's Comet (C/ 1858 L1), the Great Comet of 1861 (C/1861 J1, Tebbutt), and the Great Southern Comet of 1880 (C/1880 C1).
But the reported similarities between Comet Bennett and Donati's comet of 1858 gained worldwide attention early in April.