<figure><img src="image_1.png" /></figure>

# Erratum: “Fine Structures of Radio Bursts from Flare Star AD Leo with FAST Observations” (2023, ApJ, 953, 65)

Jiale Zhang<fnref n="1" />, Hui Tian<fnref n="1" />, Philippe Zarka<fnref n="2" />,<fnref n="3" />, Corentin K. Louis<fnref n="4" />, Hongpeng Lu<fnref n="1" />, Dongyang Gao<fnref n="5" />, Xiaohui Sun<fnref n="6" />, Sijie Yu<fnref n="7" />, Bin Chen<fnref n="7" />, Xin Cheng<fnref n="8" />,<fnref n="9" />,<fnref n="10" />, and Ke Wang<fnref n="11" />

Received 2024 May 19; published 2024 July 1

In the published article, we reported the discovery of fine structures in the radio bursts from flare star AD Leo with the observations of the Five-hundred-meter Aperture Spherical radio Telescope (FAST). We detected highly circularly polarized radio bursts in two rounds of 3 hr observations, conducted on 2021 December 2 and December 3 from 20:30 UT to 23:30 UT. We claimed in the article that all the radio bursts are right-hand circularly polarized. Recently, we found that we misunderstood the definitions of the four polarization paths of FAST. Following the same data analysis procedures, the Stokes V polarization results presented in the article actually follow the convention opposite to “PSR/IEEE” convention (van Straten et al. 2010) and the emission we detected from AD Leo should be left-hand circularly polarized.

The four polarization products (XX, YY, CI, and CR) of FAST at the L band with reference to the incoming radiation are obtained as $XX = \langle e_x e_x^* \rangle$, $YY = \langle e_y e_y^* \rangle$, $CR = \langle \text{Re}[e_x^* e_y] \rangle$, and $CI = \langle \text{Im}[e_x^* e_y] \rangle$ (Wang et al. 2023). Notice that the positions of the conjugates in CR and CI are different from the ones stated in Appendix A of the published article. By using the same definition of the Stokes V in the article ($V = -2 \times CI$), we followed the “IAU/IEEE” convention (Hamaker & Bregman 1996), which defines Stokes V as right-hand circularly polarized component minus left-hand circularly polarized component. This is the opposite of the “PSR/IEEE” convention commonly used in pulsar astronomy. The negative Stokes V values should be interpreted as left-hand circular polarization.

To test the consistency of our new sign decision on the Stokes V parameter with the consensus, we checked some pulsar observations in the public FAST data archive. We selected six targets with known signs of circular polarization (B0611+22, B0919+06, B0950+08, B1133+16, B1237+25, and B1933+16). Two of them show positive signs in Stokes V (B0611+22 and B0919+06), two of them show negative signs (B0950+08 and B1133+16), and two of them show reversal in the signs of Stokes V with time in the primary component (positive to negative for B1237+25 and negative to positive for B1933+16) under the “PSR/IEEE” convention at the L band (Gould & Lyne 1998; Han et al. 1998; Weisberg et al. 1999). Using the previous pipeline mentioned in the article, we obtained Stokes V data with opposite signs or sign patterns for all six pulsars, indicating that we indeed adopted the convention opposite to the “PSR/IEEE” convention.

In Section 5.2.3 of the published article, the correction to the sign of circular polarization suggests that the emission is o-mode if the emission comes from the northern hemisphere and x-mode from the southern hemisphere. If the emission comes from the more visible southern hemisphere, a low $\omega_p/\Omega_E$ ratio is required, implying a region with low plasma density or strong magnetic field strength. Other results in the published article are not affected.

## ORCID iDs

Jiale Zhang https://orcid.org/0009-0004-0713-405X

Hui Tian https://orcid.org/0000-0002-1369-1758

Philippe Zarka https://orcid.org/0000-0003-1672-9878

Corentin K. Louis https://orcid.org/0000-0002-9552-8822

Hongpeng Lu https://orcid.org/0000-0001-8037-5256

Dongyang Gao https://orcid.org/0000-0001-6643-2138

Xiaohui Sun https://orcid.org/0000-0002-3464-5128

Sijie Yu https://orcid.org/0000-0003-2872-2614

Bin Chen https://orcid.org/0000-0002-0660-3350

Xin Cheng https://orcid.org/0000-0003-2837-7136

Ke Wang https://orcid.org/0000-0002-7237-3856

## References

* Gould, D. M., & Lyne, A. G. 1998, MNRAS, 301, 235

* Hamaker, J. P., & Bregman, J. D. 1996, A&AS, 117, 161

* Han, J. L., Manchester, R. N., Xu, R. X., & Qiao, G. J. 1998, MNRAS, 300, 373

* van Straten, W., Manchester, R. N., Johnston, S., & Reynolds, J. E. 2010, PASA, 27, 104

* Wang, P. F., Han, J. L., Xu, J., et al. 2023, RAA, 23, 104002

* Weisberg, J. M., Cordes, J. M., Lundgren, S. C., et al. 1999, ApJS, 121, 171

<figure><img src="image_2.png" /></figure>

Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

<footnote n="1">¹School of Earth and Space Sciences, Peking University, Beijing 100871, People's Republic of China; huitian@pku.edu.cn</footnote>

<footnote n="2">²LESIA, Observatoire de Paris, Université PSL, Sorbonne Université, Université Paris Cité, CNRS, 92190 Meudon, France</footnote>

<footnote n="3">³USN, Observatoire de Paris, Université PSL, Univ Orléans, CNRS, 18330 Nançay, France</footnote>

<footnote n="4">⁴School of Cosmic Physics, DIAS Dunsink Observatory, Dublin Institute for Advanced Studies, Dublin 15, Ireland</footnote>

<footnote n="5">⁵Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, 264209, Shandong, People's Republic of China</footnote>

<footnote n="6">⁶School of Physics and Astronomy, Yunnan University, Kunming 650500, People's Republic of China</footnote>

<footnote n="7">⁷Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102, USA</footnote>

<footnote n="8">⁸School of Astronomy and Space Science, Nanjing University, Nanjing 210093, People's Republic of China</footnote>

<footnote n="9">⁹Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing 210093, People's Republic of China</footnote>

<footnote n="10">¹⁰Max Planck Institute for Solar System Research, Göttingen 37077, Germany</footnote>

<footnote n="11">¹¹Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, People's Republic of China</footnote>