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C4C0ED11-8935-4213-9354-46F366B3718E

# Jet from the enigmatic high-latitude star BP Psc and evolutionary status of its driving source

I. S. Potravnov, M. Yu. Khovritchev, S. A. Artemenko, D. N. Shakhovskoy

Submitted on 16 September 2022

## Abstract

BP Psc is an active late-type (sp:G9) star with unclear evolutionary status lying at high galactic latitude $b=-{57}^{\circ }$. It is also the source of the well collimated bipolar jet. We present results of the proper motion and radial velocity study of BP Psc outflow based on the archival $H\alpha$ imaging with the GMOS camera at 8.1-m Gemini-North telescope as well as recent imaging and long-slit spectroscopy with the SCORPIO multi-mode focal reducer at 6-m BTA telescope of SAO RAS. The 3D kinematics of the jet revealed the full spatial velocity up to $\sim$140 km$\cdot$s${}^{-1}$ and allows us to estimate the distance to BP Psc system as $D=135±40$ pc. This distance leads to an estimation of the central source luminosity ${L}_{\ast }\approx 1.2{L}_{\odot }$, indicating that it is the $\approx$1.3${M}_{\odot }$ T Tauri star with an age $t\lesssim$ 7 Myr. We measured the electron density of order ${N}_{e}\sim {10}^{2}$ cm${}^{-3}$ and mean ionization fraction $f\approx 0.04$ within the jet knots and estimated upper limit of the mass-loss rate in NE lobe as ${\stackrel{˙}{M}}_{out}\approx 1.2\cdot {10}^{-8}{M}_{\odot }\cdot y{r}^{-1}$. The physical characteristics of the outflow are typical for the low-excitation YSO jets and consistent with the magnetocentrifugal mechanism of its launching and collimation. Prominent wiggling pattern revealed in $H\alpha$ images allowed us to suppose the existence of a secondary substellar companion in a non-coplanar orbit and estimate its most plausible mass as ${M}_{p}\approx 30{M}_{Jup}$. We conclude that BP Psc is one of the closest to the Sun young jet-driving systems and its origin is possibly related to the episode of star formation triggered by expanding supershells in Second Galactic quadrant.

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Subjects: Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Astrophysics of Galaxies; Astrophysics - High Energy Astrophysical Phenomena