The Astronomer's Telegram: Top ATels

For reporting and commenting upon new observations of astronomical transients by the professional astrophysics community.

ATel 17756: Discovery of Radio Pulsation from the Radio-quiet Gamma-ray Pulsar PSR J2238+5903 with Deep FAST Observations

We report the detection of radio pulsations from the radio-quiet gamma-ray pulsar PSR J2238+5903 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST; [1]). ...
https://www.astronomerstelegram.org/?read=17756
date: 2026-04-17T04:13:40-00:00
creator: Jianli Zhang, Hui Zhu, Guanhong Lin, DeJia Zhou, Songzhan Chen, Wen-Jun Huang, Zi-Wei Ou, P. H. Thomas Tam, Sha Wu, Qiang Yuan, Yi Zhang

ATel 17755: Fermi-LAT detection of renewed high gamma-ray activity from the BL Lac PKS 0537-441

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed renewed gamma-ray activity from a source positionally consistent with the BL Lac object PKS 0537-441, also known as 4FGL J0538.8-4405 (Abdollahi et al. ...
https://www.astronomerstelegram.org/?read=17755
date: 2026-04-16T19:40:12-00:00
creator: S. Rani, E. Bronzini, P. Monti-Guarnieri, T. Lewis on behalf of the Fermi Large Area Telescope Collaboration

ATel 17754: Detection of the H-alpha and H2O+ emission lines in spectra of Comet C/2025 R3 (PanSTARRS)

Comet C/2025 R3 (PanSTARRS), a dynamically new comet, is approaching perihelion on 2026 April 20 at a heliocentric distance of about 0.49 AU (JPL-Horizons, https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=c%2F2025%20r3). ...
https://www.astronomerstelegram.org/?read=17754
date: 2026-04-15T10:24:14-00:00
creator: Federico Manzini, Alessandra C. Mura, Paolo Ochner, Andrea Farina, Luigi R. Bedin, Andrea Reguitti, Virginio Oldani

ATel 17753: Fermi-LAT detection of renewed gamma-ray activity from the FSRQ S3 0458-02

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed renewed gamma-ray activity from a source positionally consistent with the flat-spectrum radio quasar S3 0458-02, also known as 4FGL J0501.2-0158 (Abdollahi et al. ...
https://www.astronomerstelegram.org/?read=17753
date: 2026-04-14T21:15:17-00:00
creator: S. Rani, E. Bronzini, T. Lewis on behalf of the Fermi Large Area Telescope Collaboration

ATel 17752: Fermi-LAT detection of enhanced gamma-ray activity from the FSRQ NRAO 512

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed enhanced gamma-ray activity from a source positionally consistent with the flat-spectrum radio quasar NRAO 512, also known as 4FGL J1640.4+3945 (Abdollahi et al. ...
https://www.astronomerstelegram.org/?read=17752
date: 2026-04-13T21:37:52-00:00
creator: Janeth Valverde, Giovanni La Mura, on behalf of the Fermi Large Area Telescope Collaboration

ATel 17751: Einstein Probe detection of a new outburst from XRB IGR J17331-2406

We report the detection of a new outburst from XRB IGR J17331-2406 with the Wide-field X-ray Telescope (WXT) onboard the Einstein Probe (EP). The source was discovered in 2004 (Atel #328) and has exhibited multiple outbursts in gamma-ray band since then. ...
https://www.astronomerstelegram.org/?read=17751
date: 2026-04-12T10:07:46-00:00
creator: A. Li, C. Y. Wang, X. H. Tang, Z. X. Ling on behalf of the Einstein Probe team

ATel 17750: Corrigendum to Atel #17748

In ATel #17748 we announced the discovery of an apparent nova M31N 2026-04a. Unfortunately, the reported position of the nova was incorrect. The correct position of M31N 2026-04a is R.A. ...
https://www.astronomerstelegram.org/?read=17750
date: 2026-04-11T18:58:19-00:00
creator: K. Hornoch, M. Myslivec, A. W. Shafter

ATel 17749: WW Lyn - X-ray brightening

We report an increase in X-ray flux from the cataclysmic variable, WW Lyn, RA=07:34:07.8; DEC=+38:10:40.1 In a slew from XMM-Newton of 31/03/2026 the flux from WW Lyn was observed to be 5.7 & plusmn;1.1 & times; 10-12 ergs/s/cm2 in the soft X-ray (0.2-2 keV) band and 1.3 & plusmn;0.2 & times; 10-11 ergs/s/cm2 in the broad (0.2-12 keV) band. ...
https://www.astronomerstelegram.org/?read=17749
date: 2026-04-11T18:08:39-00:00
creator: Richard Saxton, Jan-Uwe Ness, Felix Fuerst

ATel 17748: Discovery of an Apparent Nova in M31, M31N 2026-04a

We report the discovery of an apparent nova in M31 on a co-added 2400-s H_alpha CMOS frame taken on 2026 Apr. 8.079 UT with the 0.4-m telescope at Belec nad Orlici. ...
https://www.astronomerstelegram.org/?read=17748
date: 2026-04-10T23:30:06-00:00
creator: K. Hornoch, M. Myslivec, A. W. Shafter

ATel 17747: XRISM/Xtend Transient Search (XTS) detected an X-ray flare or outburst from RX J0101.0-7206

XRISM/Xtend Transient Search (XTS) detected an X-ray flare flare or outburst from an X-ray source XRISM J0101-7207 on 2026-04-09 TT. The source position is determined to be (R.A., Dec.) = (15.255, -72.114), with a systematic error of & sim; 40 arcsec. ...
https://www.astronomerstelegram.org/?read=17747
date: 2026-04-10T07:25:06-00:00
creator: M. Yoshimoto, T. Yoneyama, Y. Kanemaru, Y. Omiya, Y. Uchida, M. Audard, E. Behar, K. Fukushima, T. Hakamata, S. Inoue, Y. Ishihara, C. Kang, T. Kiyomoto, T. Kohmura, H. Kuramoto, J. Kurashima, Y. Maeda, H. Matsumoto, A. Miyamoto, M. Mizumoto, K. Mori, Y. Motogami, T. Narita, M. Nobukawa, H. Noda, S. Ogawa, Y. Sakamoto, M. Shidatsu, H. Takahashi, T. Takagi, S. Takatsuka, F. Takisawa, Y. Terada, Y. Terashima, Y. Tsuboi, H. Uchida, A. Yoshimoto