List of exceptional asteroids
Largest by diameter
Estimating the sizes of asteroids from observations is difficult due to their irregular shapes, varying albedo, and small angular diameter. For example, pure C-type asteroids are much darker than most.

List of exceptional asteroids

Section Title: Largest by diameter
Table Section Text: Estimating the sizes of asteroids from observations is difficult due to their irregular shapes, varying albedo, and small angular diameter. For example, pure C-type asteroids are much darker than most.

Name	Diameter (km) (geometric mean)	Dimensions (km)	Mean distance from Sun (in AU)	Date discovered	Discoverer	Class

1 Ceres	946±2	965×962×891	2.766	January 1, 1801	Piazzi, G.	G

4 Vesta	525.4±0.2	572.6 × 557.2 × 446.4 ± 0.2	2.362	March 29, 1807	Olbers, H. W.	V

2 Pallas	512±3	550±4 × 516±3 × 476±3 km	2.773	March 28, 1802	Olbers, H. W.	B

10 Hygiea	431±7	530×407×370	3.139	April 12, 1849	de Gasparis, A.	C

704 Interamnia	326	350×304	3.062	October 2, 1910	Cerulli, V.	F

52 Europa	315	380×330×250	3.095	February 4, 1858	Goldschmidt, H.	C

511 Davida	289	357×294×231	3.168	May 30, 1903	Dugan, R. S.	C

87 Sylvia	286	385×265×230	3.485	May 16, 1866	Pogson, N. R.	X

65 Cybele	273	302×290×232	3.439	March 8, 1861	Tempel, E. W.	C

15 Eunomia	268	357×255×212	2.643	July 29, 1851	de Gasparis, A.	S

3 Juno	258	320×267×200	2.672	September 1, 1804	Harding, K. L.	S

31 Euphrosyne	256	255.9 ± 5.8 km	3.149	September 1, 1854	Ferguson, J.	C

624 Hektor	241	370×195(×195)	5.235	February 10, 1907	Kopff, A.	D

88 Thisbe	232	221×201×168	2.769	June 15, 1866	Peters, C. H. F.	B

324 Bamberga	229	229×235×229	2.684	February 25, 1892	Palisa, J.	C

451 Patientia	225	225×234	3.059	December 4, 1899	Charlois, A.

532 Herculina	222	260×220×215	2.772	April 20, 1904	Wolf, M.	S

48 Doris	222	278×142	3.108	September 19, 1857	Goldschmidt, H.	C

375 Ursula	216	189×192×194	3.126	September 18, 1893	Charlois, A.

107 Camilla	215	285×205×170	3.476	November 17, 1868	Pogson, N. R.	C

45 Eugenia	213	305×220×145	2.720	June 27, 1857	Goldschmidt, H.	F

7 Iris	213	240×200×200	2.386	August 13, 1847	Hind, J. R.	S

29 Amphitrite	212	233×212×193	2.554	March 1, 1854	Marth, A.	S

423 Diotima	209	171×138	3.065	December 7, 1896	Charlois, A.	C

19 Fortuna	208	225×205×195	2.442	August 22, 1852	Hind, J. R.	G

13 Egeria	206	217×196	2.576	November 2, 1850	de Gasparis, A.	G

24 Themis	198	spheroid 198	3.136	April 5, 1853	de Gasparis, A.	C

94 Aurora	197	225×173	3.160	September 6, 1867	Watson, J. C.	C

702 Alauda	195	97.365±1.6 km	3.195	July 16, 1910	Helffrich, J.	C/B

121 Hermione	190	268×186×183	3.457	May 12, 1872	Watson, J. C.	C

259 Aletheia	190	178×190	3.135	June 28, 1886	Peters, C. H. F.	C/P/X

372 Palma	189	188	3.149	August 19, 1893	Charlois, A.	B

128 Nemesis	188	188	2.751	November 25, 1872	Watson, J. C.	C

6 Hebe	186	205x185x170	2.426	July 1, 1847	Hencke, K. L.	S

16 Psyche	186	240×185×145	2.924	March 17, 1852	de Gasparis, A.	M

120 Lachesis	174	184x144	3.301	April 10, 1872	Borrelly, A.	C

41 Daphne	174	213x160	2.765	May 22, 1856	Goldschmidt, H.	C

9 Metis	174	222x182x130	2.385	April 25, 1848	Graham, A.	S

Sentence(s)

Euphrosyne (designation: 31 Euphrosyne) is the 12th-largest asteroid discovered by Ferguson on September 1, 1854.

final_sentence: Euphrosyne (designation: 31 Euphrosyne) is the 12th-largest asteroid discovered by Ferguson on September 1, 1854.