Program: GN-2014B-Q-16

We have identified an infrared excess at a young white dwarf that is consistent with a 10 Jupiter mass planet for single star evolution. The host star is strikingly similar in both mass and effective temperature to the one confirmed white dwarf member of the Pleiades, and thus consistent with a total age of 125 Myr. The K-band and IRAC colors, and inferred absolute magnitudes at the white dwarf distance are all consistent with an early to mid T-type object, and we propose GNIRS spectroscopy to determine the nature of the excess. While a chance alignment with a red extragalactic source is possible, it would have to be within 1" of the star, and no indications are apparent in our K-band images. Another distinct possibility is a circumstellar disk resulting from the merger of two white dwarfs -- such disks have long been suspected, but never seen, and would be an important discovery. If a giant plant is confirmed, we may have the opportunity to later study its atmosphere directly, by resolving the source with laser adaptive optics. Regardless, a giant planet around such a massive remnant would indicate that planet formation occurs at 6-8 solar mass B stars, and this would also be a major find.