250 Bettina

{{Short description|Main-belt asteroid}}

{{Use dmy dates|date=October 2019}}

{{Infobox planet

| minorplanet = yes

| background = #D6D6D6

| name = 250 Bettina

| image = 250Bettina (Lightcurve Inversion).png

| image_scale =

| caption = A three-dimensional model of 250 Bettina based on its light curve.

| discoverer = Johann Palisa

| discovered = 3 September 1885

| mpc_name = (250) Bettina

| pronounced = {{IPA|de|bɛˈtiːnaː|lang}}[https://www.germannames.de/wiki/Bettina (German Names)]

| alt_names = A885 RA

| mp_category = Main belt

| epoch = 31 July 2016 (JD 2457600.5)

| orbit_ref =

| semimajor = {{Convert|3.14906|AU|Gm|abbr=on}}

| perihelion = {{Convert|2.7325|AU|Gm|abbr=on}}

| aphelion = {{Convert|3.5657|AU|Gm|abbr=on|lk=on}}

| eccentricity = 0.13229

| period = 5.59 yr (2041.1 d)

| inclination = 12.819°

| asc_node = 23.862°

| arg_peri = 76.692°

| mean_anomaly = 56.902°

| avg_speed = 16.78 km/s

| dimensions = {{val|120.995|2.212|ul=km}}

| mass = (2.389 ± 1.157/0.547){{e|18}} kg

| density = 3.524 ± 1.707/0.806 g/cm{{sup|3}}{{efn|Assuming a diameter of 109 ± 5 km.}}

| rotation = {{Convert|5.0545|h|d|abbr=on|lk=on}}
5.055 h

| spectral_type = M

| abs_magnitude = 7.72

| albedo = {{val|0.112|0.019}}

| single_temperature =

| mean_motion = {{Deg2DMS|0.17637|sup=ms}} / day

| observation_arc = 130.62 yr (47710 d)

| uncertainty = 0

}}

250 Bettina is a large main belt asteroid that was discovered by Austrian astronomer Johann Palisa on September 3, 1885, in Vienna. It was named in honour of Baroness Bettina von Rothschild (née de Rothschild; 1858–1892), wife of Baron Albert von Rothschild who had bought the naming rights for £50.Observatory, vol. 8, p. 63, 1885 & vol. 9, p. 142, 1886; see also The Guinness Book of Astronomy Facts and Feats Patrick Moore page 96 {{ISBN|0-900424-76-1}} Based upon the spectrum, it is classified as an M-type asteroid.

In 1988, the asteroid was observed from the Collurania-Teramo Observatory, allowing a light curve to be produced that showed "an irregular behavior with a deeper minimum and a narrower maximum". The data showed a rotation period of 5.055 hours and a brightness variation of 0.17 ± 0.01 in magnitude. The ratio of the lengths of the major to minor axes for this asteroid were found to be 1.51 ± 0.03.