GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
- IPN triangulation of GRB031130 (large error box)
- GRB031111A, prompt optical observations
- GRB 030329: Planned XMM-Newton Observation
- IPN triangulation of GRB031120 (two large error boxes)
- GRB 031111B (= H2925) : Kyoto Optical Observation
- IPN/HETE localization of GRB031109 (=H2917; large error box)
- IPN detection of activity from SGR1806-20
- GRB 031111, Radio observations
- IPN triangulation of GRB031114 (large error box)
- IPN triangulation of GRB031107 (two large error boxes)
- GRB 031111: Optical observations
- GRB 031111, optical observations
- SN 2003jd (SN/GRB?) -- X-ray Observations
- HETE Prompt GRB Spectral Analyses
- IPN triangulation of GRB031111 (=H2924): small error box
- XRF031109 (=H2919): A very long XRF localized by HETE
- IPN triangulation of GRB031108 (large error box)
- GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
- GRB030929/SN2003jd association unlikely based on IPN localiztion
- IPN triangulation of GRB031027 (small error box)
- IPN triangulation of GRB031026B (large error box)
- Lulin optical follow-up observations of GRB031026
- SN 2003jd (SN/GRB?), Radio Observations
- SN 2003jd (SN/GRB?) - possible association with GRB 030929
- GRB 031026: Further Ic Observations
- GRB 031026 (=H2882): Evidence for High Redshift from Prompt
- Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
- IPN triangulation of GRB031024 (single error box)
- GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
- GRB 031026: Ic Observations
- GRB031026 : KISO optical follow-up observation
- IPN triangulation of GRB031024 (annulus)
- IPN triangulation of GRB031020 (large error box)
- GRB030329: radio observations at RT-22 (CrAO)
- IPN triangulation of GRB031016 (two large error boxes)
- IBAS alert 1180 refers to a burst from SGR 1806-20
- HETE Prompt GRB Light Curves and Color-Color Diagrams
- IPN triangulation of GRB031014 (annulus)
- Ongoing Bursting Activity from SGR 1806-20 detected with IBAS
- XRF 030824: additional observations at CFHT
- SGR1806-20 bursts on 031008. Helicon detection and small error box.
- IPN triangulation of GRB031008 (annulus)
- SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
- IPN detection of continued activity from SGR1806-20
- IPN triangulation of GRB031007 (two large error boxes)
- XRF 030723: Subaru Optical Observations
- IPN triangulation of GRB031004B (annulus)
- IPN triangulation of GRB031004A (short/hard; annulus)
- IPN triangulation of GRB030929 (short/hard; annulus)
- A burst from SGR 1806-20 detected with IBAS
- XRF 030824: Early follow-up observation at Kiso observatory
- XRF 030824: observations at CFHT
- IPN triangulation of GRB030926 (short/hard; large error box)
- IPN triangulation of GRB030922B (large error box)
- XRF 030723: Detection of the likely host galaxy
- XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
- XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
- IPN triangulation of GRB030922A (large error box)
- IPN triangulation of GRB030921 (large error box)
- IPN triangulation of GRB030919 (large error box)
- GRB030922 triangulation (annulus)
- GRB030913: Subaru Optical Observations
- GRB 030913: ROTSE-3c Optical Observations
- GRB030913: OT's limit by MASTER
- GRB030921 triangulation (annulus)
- GRB030913, candidate afterglow observations
- GRB 030913, optical candidate
- GRB030913: AAVSO optical observations
- GRB 030913, BOOTES observations
- GRB030913 (=H2849): Confirmation of the Flight Localization
- IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
- GRB030913 (=H2849): TAROT Observations
- GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
- Magellan Observations of GRB030725 (=H2779)
- GRB030913 (=H2849): A GRB Possibly Localized by HETE
- IPN triangulation of GRB030908 (annulus)
- GRB 030913: Optical limit at RIKEN
- XRF 020427: Gemini-South Spectroscopic Observations of the Host
- XRF030824: Optical observations
- IPN triangulation of GRB030903 (large error box)
- IBAS detection of bursts from SGR 1806-20
- Radio Observations of SGR1806-20
- IPN triangulation of GRB030831 (annulus)
- IPN triangulation of GRB030830 (large error box)
- GRB 030824: Candidate Follow-Up
- INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
- IPN triangulation of GRB030827 (large error box)
- GRB 030823 observation at Ouda
- XRF030824: Second-epoch Palomar observations
- XRF030824: optical observations
- IPN triangulation of GRB030822 (annulus)
- GRB030823: optical observations
- GRB030823: Palomar observations
- XRF030824: Palomar observations
- GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
- GRB030823: optical observation at Tokyo Tech
- RAPTOR observations of GRB030823
- Lulin follow-up observations of GRB030823
- IPN triangulation of GRB030821 (=H2814; refined error box)
- GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN