High Accuracy Radial Velocity Planet Searcher
HD 41248 was investigated in the High Accuracy Radial Velocity Planet Searcher (HARPS) and initially thought not to have planets, but review of its spectrum showed it to have two super-earths with orbital periods of 18.357 days and 25.648 days and minimum masses 12.3 and 8.6 times that of the Earth. The planets are in a 7:5 mean motion resonance. The existence of the planets has been called into question as being a possible false detection due to stellar activity, with a cycle of 25 days related to the star's rotational period. The original researchers conceded small planet signals could be difficult to unravel from signal noise and noted that the star had become more active in recent years, but in reanalysing all the data concluded that the stability of the radial velocity signals over ten years strengthened the case for the planet hypothesis. They add that more conclusive proof could come as instruments operating in the near infrared such as CARMENES or the Habitable Zone Planet Finder (HPF) become operational.