| Minorplanet: | yes |
| Background: |
|
| 738 Alagasta | |
| Mpc Name: | (738) Alagasta |
| Alt Names: | 1913 QO |
| Discovered: | 7 January 1913 |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Eccentricity: | 0.055023 |
| Semimajor: | 3.0369AU |
| Perihelion: | 2.8698AU |
| Aphelion: | 3.204abbr=onNaNabbr=on |
| Period: | 1933.1days |
| Inclination: | 3.5344° |
| Asc Node: | 132.115° |
| Arg Peri: | 41.826° |
| Rotation: | 18.86abbr=onNaNabbr=on |
| Abs Magnitude: | 10.13 |
| Mean Motion: | / day |
| Observation Arc: | 37720order=flipNaNorder=flip |
| Uncertainty: | 0 |
| Moid: | 1.87517AU |
| Jupiter Moid: | 1.76226AU |
| Tisserand: | 3.236 |
738 Alagasta is a main belt asteroid. It was discovered from Heidelberg on 7 January 1913 by German astronomer Franz Kaiser. The asteroid was named in honor of Gau-Algesheim, previously Alaghastesheim, which is the home city of the discoverer's family. This body is orbiting at a distance of with a period of 1933.1days and an eccentricity of 0.055. The orbital plane is inclined at an angle of 3.53° to the plane of the ecliptic.
Photometric measurements made of the asteroid during 2015 produced a light curve that showed a rotation period of with a brightness variation of 0.11 in magnitude. The asteroid is roughly 63 km in diameter and has a low albedo.