| Minorplanet: | yes |
| 977 Philippa | |
| Background: |
|
| Discovery Ref: |   |
| Discovered: | 6 April 1922 |
| Mpc Name: | (977) Philippa |
| Alt Names: | A922 GA1922 LV A914 YA1914 YA A919 XA1919 XA |
| Named After: | Philippe de Rothschild |
| Mp Category: | main-belt  background  |
| Orbit Ref: |   |
| Epoch: | 31 May 2020 (JD 2459000.5) |
| Uncertainty: | 0 |
| Observation Arc: | 105.05 yr (38,370 d) |
| Perihelion: | 3.0366 AU |
| Semimajor: | 3.1178 AU |
| Eccentricity: | 0.0260 |
| Period: | 5.51 yr (2,011 d) |
| Mean Motion: | / day |
| Inclination: | 15.174° |
| Asc Node: | 75.739° |
| Arg Peri: | 72.694° |
| Mean Diameter: | |
| Albedo: | |
| Spectral Type: |
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| Abs Magnitude: | 9.9 |
977 Philippa (prov. designation: or) is a large background asteroid from the outer regions of the asteroid belt, approximately 65km (40miles) in diameter. It was discovered on 6 April 1922, by Russian–French astronomer Benjamin Jekhowsky at the Algiers Observatory in Northern Africa. The C-type asteroid is likely irregular in shape and has a rotation period of 15.4 hours. It was named after French financier Baron Philippe de Rothschild (1902–1988).
Philippa is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements. It orbits the Sun in the outer asteroid belt at a distance of 3.0–3.2 AU once every 5 years and 6 months (2,011 days; semi-major axis of 3.12 AU). Its orbit has an eccentricity of 0.03 and an inclination of 15° with respect to the ecliptic.
The asteroid was first observed as A914 YA (1914 YA) at Heidelberg Observatory in December 1912. The body's observation arc begins at Vienna Observatory on 1 May 1922, or one month after its official discovery observation at Algiers.
This minor planet was named after French financier Baron Philippe de Rothschild (1902–1988). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 .
In the Tholen classification-SMASS classification, Philippa is a common carbonaceous C-type asteroid, while in both the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), the asteroid is an X-type.
In April 2004, a rotational lightcurve of Philippa was obtained from photometric observations by Brian Warner at the Palmer Divide Observatory in Colorado. Analysis of the classical bimodal lightcurve gave a rotation period of hours with a high brightness amplitude of magnitude, indicative of an irregular, non-spherical shape
According to the survey carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Philippa measures between 65.4 and 65.9 kilometers in diameter and its surface has an albedo between 0.05 and 0.06. The Collaborative Asteroid Lightcurve Link adopts the results from IRAS, that is, an albedo of 0.0555 and a diameter of 65.67 kilometers based on an absolute magnitude of 9.67. In April 2014, Philippa was also subject to an asteroid occultation, timed observations when the asteroid passes in front of a distant star. The measurements gave an estimated diameter of 65 kilometers.