2018年IOAA数据分析第2题-双星系统中的致密天体
(D2) Compact Object in a Binary System [75 points]
Astronomers discovered an extraordinary binary system in the constellation of Auriga during the course of the Apache Point Observatory Galactic Evolution Experiment (APOGEE). In these questions, you will try to analyse the data and recreate their discovery for yourself.
The research team is aiming to find compact stars in binary systems using the radial velocity (RV) technique. They examined archival APOGEE spectra of “single” stars and measured the apparent variation of their RV within this data. Among ~200 stars with the highest accelerations, researchers searched for periodic photometric variations in data from the All-Sky Automated Survey for Supernovae (ASAS-SN) that might be indicative of transits, ellipsoidal variations or starspots. After this process, they spotted a star named 2M05215658+4359220, with a large variation in RV and photometric variability.
2.1. The following table presents the radial velocity measurements of 2M05215658+4359220 during three epochs of APOGEE spectroscopic observation. Here we assume the variation of its RV is due to the existence of an unseen companion. The proper motion of the stars can be ignored.
| Observation | MJD | RV(km·s-1) | Uncertainty(km·s-1) |
|---|---|---|---|
| 56204.9537 | -37.417 | 0.011 | |
| 56229.9213 | 34.846 | 0.010 | |
| 56233.8732 | 42.567 | 0.010 |
(D2.1.1) (6 points) Use the data and a simple linear model to obtain an initial estimate of the apparent maximum acceleration of the star:
