STARITHM
High-energy neutrino detected by IceCube with potential astrophysical origins; no counterparts found.
AI Summary
IceCube detected a high-energy neutrino event likely of astrophysical origin on 2026-09-19. Follow-up observations by Fermi-LAT and ZTF/GROWTH found no significant gamma-ray or optical counterparts.
Measurements
| Event | IceCube-260919A |
|---|---|
| Event ID | IceCube-260919A |
| Source | IceCube |
| Alert type | NEUTRINO |
| Significance | high |
| Trigger time (UTC) | Sat, 19 Sep 2026 06:52:15 GMT |
| Right ascension (J2000) | 111.05° |
| Declination (J2000) | 6.43° |
| Position error radius | 0.27° (16.2′) |
| Position from | notice icecube.gold_bronze_track_alerts |
| GCN notices | 2 |
| GCN circulars | 4 |
Every localisation reported in Circulars (1)
| Instrument | Of | Error | Circular |
|---|---|---|---|
| IceCube | burst | 18.6′ (90%) | GCN 45645 |
Observations (5)
Values parsed from the Circular text; each row names its Circular.
| Time since trigger | Band | Value | Telescope | Circular |
|---|---|---|---|---|
| T+2.2 d | g | > 20.5 mag (limit) | Palomar 48-inch telescope | GCN 45936 |
| T+2.2 d | r | > 20.5 mag (limit) | Palomar 48-inch telescope | GCN 45936 |
| — | >100 MeV | < 1.20e-10 ph cm^-2 s^-1 (limit) | Fermi | GCN 45706 |
| — | >100 MeV | < 7.10e-9 ph cm^-2 s^-1 (limit) | Fermi | GCN 45706 |
| — | >100 MeV | < 1.10e-7 ph cm^-2 s^-1 (limit) | Fermi | GCN 45706 |
Notices (1)
IceCube — NEUTRINO · Sat, 19 Sep 2026 06:52:15 GMT
GCN Circulars (4)
GCN-45936 — IceCube-260919A
· Tue, 13 Oct 2026 08:08:56 GMT
The Zwicky Transient Facility (ZTF) and GROWTH collaborations conducted observations of the localization region of the neutrino event IceCube-260919A using the Palomar 48-inch telescope, but no candidate counterparts were detected. This observation was part of a neutrino follow-up program and covered 67.3% of the reported localization region, with a typical depth of 20.5 mag.
GCN-45706 — IceCube-260919A
· Wed, 23 Sep 2026 14:37:59 GMT
The Fermi-LAT collaboration reported on the analysis of gamma-ray observations following the detection of a high-energy neutrino event, IC260919A, by IceCube. No significant new gamma-ray emission was found within the 90% localization error of the neutrino event, with upper limits on the flux provided for different integration times.
GCN-45663 — IceCube-260919A
· Sun, 20 Sep 2026 22:21:26 GMT
The IceCube Neutrino Observatory conducted a search for additional neutrino events related to the alert IceCube-260919A, finding no significant excess of track events in both a 1000-second and a 2-day time window. The sensitivity to neutrino point sources was reported, indicating the detector's capability to detect events in the specified energy range.
GCN-45645 — IceCube-260919A
· Sat, 19 Sep 2026 14:38:02 GMT
On September 26, 2019, the IceCube Neutrino Observatory detected a high-energy neutrino event with a high probability of being of astrophysical origin. The event was refined to a specific direction in the sky, with no known gamma-ray sources in the uncertainty region, making it a significant candidate for further astrophysical study.
AI summary generated Thu, 29 Oct 2026 22:48:50 GMT.