_version_ 1866909753504956416
author Close, Laird M.
van Capelleveen, Richelle F.
Weible, Gabriel
Wagner, Kevin
Haffert, Sebastiaan Y.
Males, Jared R.
Ilyin, Ilya
Kenworthy, Matthew A.
Li, Jialin
Long, Joseph D.
Ertel, Steve
Ginski, Christian
Weinberger, Alycia J.
Follette, Kate
Liberman, Joshua
Twitchell, Katie
Johnson, Parker
Kueny, Jay
Apai, Daniel
Doyon, Rene
Foster, Warren
Gasho, Victor
Van Gorkom, Kyle
Guyon, Olivier
Kautz, Maggie Y.
McLeod, Avalon
McEwen, Eden
Pearce, Logan
Schatz, Lauren
Hedglen, Alexander D.
Wu, Ya-Lin
Isbell, Jacob
Power, Jenny
Carlson, Jared
Close, Emmeline
Tonucci, Elena
Mars, Matthijs
author_facet Close, Laird M.
van Capelleveen, Richelle F.
Weible, Gabriel
Wagner, Kevin
Haffert, Sebastiaan Y.
Males, Jared R.
Ilyin, Ilya
Kenworthy, Matthew A.
Li, Jialin
Long, Joseph D.
Ertel, Steve
Ginski, Christian
Weinberger, Alycia J.
Follette, Kate
Liberman, Joshua
Twitchell, Katie
Johnson, Parker
Kueny, Jay
Apai, Daniel
Doyon, Rene
Foster, Warren
Gasho, Victor
Van Gorkom, Kyle
Guyon, Olivier
Kautz, Maggie Y.
McLeod, Avalon
McEwen, Eden
Pearce, Logan
Schatz, Lauren
Hedglen, Alexander D.
Wu, Ya-Lin
Isbell, Jacob
Power, Jenny
Carlson, Jared
Close, Emmeline
Tonucci, Elena
Mars, Matthijs
contents Excellent (<25 mas) H$_α$ images of the star TYC 5709-354-1 led to the discovery of a rare H$_α$ protoplanet. This star was discovered by the WISPIT survey to have a large multi-ring transitional disk, and is hereafter WISPIT 2. Our H$_α$ images of 2025, April 13 and April 16 discovered an accreting (H$_α$ in emission) protoplanet: WISPIT 2b (r=309.43$\pm$1.56 mas; (~54 au deprojected), PA=242.21$\pm$0.41 degrees) likely clearing a dust-free gap between the two brightest dust rings in the transitional disk. Our SNR=12.5 detection gave an H$_α$ ASDI contrast of (6.5$\pm$0.5)x10$^{-4}$ and a H$_α$ line flux of (1.29$\pm$0.28)x10$^{-15}$ erg/s/cm$^2$. We also present L' photometry from LBT/LMIRcam of the planet (L'=15.30$\pm$0.05 mag) which, when coupled with an age of 5.1$^{+2.4}_{-1.3}$ Myr, yields a planet mass estimate of 5.3$\pm$1.0 Mjup from the DUSTY evolutionary models. WISPIT 2b is accreting at 2.25$^{-0.17}_{+3.75}$x10$^{-12}$ Msun/yr. WISPIT 2b is very similar to the other H$_α$ protoplanets in terms of mass, age, flux, and accretion rate. The inclination of the system (${\it i}$=44 degrees) is also, surprisingly, very similar to the other known H$α$ protoplanet systems which all cluster from 37$\leq{\it i}\leq$52 degrees. We argue this clustering has only a ~1.0% (2.6 sigma) probability of occurring randomly, and so we speculate that magnetospherical accretion might have a preferred inclination range (~37-52 degrees) for the direct (cloud free, low extinction) line of sight to the H-alpha line formation/shock region. We also find at 110mas (~15au deprojected) a close companion candidate (CC1) which may be consistent with an inner dusty 9$\pm$4 Mjup planet.
format Preprint
id arxiv_https___arxiv_org_abs_2508_19046
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Wide Separation Planets In Time (WISPIT): Discovery of a Gap H$α$ Protoplanet WISPIT 2b with MagAO-X
Close, Laird M.
van Capelleveen, Richelle F.
Weible, Gabriel
Wagner, Kevin
Haffert, Sebastiaan Y.
Males, Jared R.
Ilyin, Ilya
Kenworthy, Matthew A.
Li, Jialin
Long, Joseph D.
Ertel, Steve
Ginski, Christian
Weinberger, Alycia J.
Follette, Kate
Liberman, Joshua
Twitchell, Katie
Johnson, Parker
Kueny, Jay
Apai, Daniel
Doyon, Rene
Foster, Warren
Gasho, Victor
Van Gorkom, Kyle
Guyon, Olivier
Kautz, Maggie Y.
McLeod, Avalon
McEwen, Eden
Pearce, Logan
Schatz, Lauren
Hedglen, Alexander D.
Wu, Ya-Lin
Isbell, Jacob
Power, Jenny
Carlson, Jared
Close, Emmeline
Tonucci, Elena
Mars, Matthijs
Earth and Planetary Astrophysics
Instrumentation and Methods for Astrophysics
Excellent (<25 mas) H$_α$ images of the star TYC 5709-354-1 led to the discovery of a rare H$_α$ protoplanet. This star was discovered by the WISPIT survey to have a large multi-ring transitional disk, and is hereafter WISPIT 2. Our H$_α$ images of 2025, April 13 and April 16 discovered an accreting (H$_α$ in emission) protoplanet: WISPIT 2b (r=309.43$\pm$1.56 mas; (~54 au deprojected), PA=242.21$\pm$0.41 degrees) likely clearing a dust-free gap between the two brightest dust rings in the transitional disk. Our SNR=12.5 detection gave an H$_α$ ASDI contrast of (6.5$\pm$0.5)x10$^{-4}$ and a H$_α$ line flux of (1.29$\pm$0.28)x10$^{-15}$ erg/s/cm$^2$. We also present L' photometry from LBT/LMIRcam of the planet (L'=15.30$\pm$0.05 mag) which, when coupled with an age of 5.1$^{+2.4}_{-1.3}$ Myr, yields a planet mass estimate of 5.3$\pm$1.0 Mjup from the DUSTY evolutionary models. WISPIT 2b is accreting at 2.25$^{-0.17}_{+3.75}$x10$^{-12}$ Msun/yr. WISPIT 2b is very similar to the other H$_α$ protoplanets in terms of mass, age, flux, and accretion rate. The inclination of the system (${\it i}$=44 degrees) is also, surprisingly, very similar to the other known H$α$ protoplanet systems which all cluster from 37$\leq{\it i}\leq$52 degrees. We argue this clustering has only a ~1.0% (2.6 sigma) probability of occurring randomly, and so we speculate that magnetospherical accretion might have a preferred inclination range (~37-52 degrees) for the direct (cloud free, low extinction) line of sight to the H-alpha line formation/shock region. We also find at 110mas (~15au deprojected) a close companion candidate (CC1) which may be consistent with an inner dusty 9$\pm$4 Mjup planet.
title Wide Separation Planets In Time (WISPIT): Discovery of a Gap H$α$ Protoplanet WISPIT 2b with MagAO-X
topic Earth and Planetary Astrophysics
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2508.19046