RZ Piscium


RZ Piscium is a UX Orionis type variable star away, in the constellation Pisces. Over the years, the star has been found to brighten and dim erratically, dimming by as much as a tenth of its usual luminosity. RZ Piscium has been found to emit large amounts of infrared radiation, suggesting the presence of a substantial mass of gas and dust orbiting the star, possibly from a "disrupted planet".

Disrupted planet

Because of the infrared excess and rapid light variations, astronomers conclude that:
According to astronomer Ben Zuckerman:

Observations

In 2017, RZ Piscium was studied using the XMM-Newton satellite, the C. [Donald Shane telescope|Shane 3-meter telescope] at Lick Observatory in California and the OH-Suppressing Infrared [Integral Field Spectrograph|10-meter Keck I telescope] at W. M. Keck Observatory in Hawaii. The temperature of the star was found to be about the same as the Sun. Further, the star was found to produce about a thousand times more x-rays than the Sun, suggesting that the star is relatively young. On the other hand, RZ Piscium was found to contain a relatively small amount of surface lithium, which suggests the star is between 30 − 50 million years old; this is somewhat "old" for a star with so much circumstellar dust. Most young stars that are as dusty as RZ Piscium may be producing planets, but given its relatively advanced age, RZ Piscium may be destroying and consuming its planets instead.
In 2020, a red dwarf companion with the mass of 0.12 Solar mass was detected with a projected separation of 23 AU from the primary star. The incandescence of the companion star thus make up about one third of excess infrared emission previously attributed to the dust.
Observations with TESS did result in the detection of 24 transits by exocomets. The transits have absorption depths between 1-20%. This is the second system, after Beta Pictoris that shows a large population of comets. The transit rate is about double compared to Beta Pictoris, with 0.40 exocomets per day for RZ Piscium. The exocomets have a size of 1-7 km.