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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"35987 results found.
- GRB 030328: Optical observations
- Re: GRB 030328: Finding chart
- GRB 030328: Finding chart
- GRB 030328: Optical afterglow candidate
- GRB030131, BVRcIc field photometry
- Possible GRB030323 localized by INTEGRAL
- IPN triangulation of GRB030325 (final analysis)
- IPN triangulation of GRB030326 (single small error box)
- GRB 030323: SARA Optical Observations
- IPN triangulation of GRB030325 (single small error box)
- GRB030324, optical observations
- IPN triangulation of GRB030325 (two small error boxes)
- GRB 030324: TAROT optical observations
- GRB 030324 (HETE #2641): Optical observations
- GRB030324, Optical Observations
- GRB030323: Upper limits from recent and historical observations.
- GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
- GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
- GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
- VLT/FORS2 spectra of GRB 030323
- GRB030323, ROTSE-III detection of possible optical counterpart
- GRB030323, optical observations
- GRB030324, BVRcIc field photometry
- GRB030323, possible optical counterpart
- GRB030323, BVRcIc field calibration
- GRB 030324 optical observations
- GRB 030320: Optical Observations
- GRB 030324, optical observations
- IPN triangulation of GRB030320B (annulus)
- IPN triangulation of GRB030320 (small error box)
- IPN triangulation of GRB030320
- Possible GRB 030320 localized by INTEGRAL
- IPN upper limit to a GRB associated with SN2003L
- IPN triangulation of GRB030317 (annulus)
- IPN triangulation of GRB030307 (annulus)
- GRB 030227: Optical limit at RIKEN
- GRB 030226 Optical observations
- IPN triangulation of GRB030306 (single small error box - REVISED)
- GRB030226: Optical observations at Asiago
- IPN triangulation of GRB030306 (single small error box)
- IPN triangulation of GRB030306 (two small error boxes)
- IPN triangulation of GRB030306 (intense; annulus only so far)
- GRB 030226: Optical observations
- IPN triangulation of GRB030304 (annulus)
- GRB 030227: Optical observations
- GRB030226, BVRc observations
- Chandra detection of the X-ray afterglow of GRB 030226
- GRB 030226, further optical/NIR imaging
- GRB030227, optical observations
- GRB 030226: Ic Observations
- GRB030227: Kiso optical upper limit
- IPN triangulation of GRB030301 (annulus)
- IPN triangulation of GRB030228 (annulus)
- GRB030227, BVRcIc field photometry
- GRB030226, BVRcIc field calibration
- GRB 030227 optical afterglow
- 030302: NOT A GRB
- 030228: NOT A GRB
- GRB 030228, optical observations
- GRB 030226: Steep Decline
- GRB 030227: Confirmed Optical Afterglow (S1-A)
- GRB 030226: R band polarimetric observations
- GRB 030226: Optical observations
- GRB 030227: fading of candidate optical afterglow 'S1-A'
- GRB030227:Optical observations
- GRB 20030226: Upper limits from recent and historical observations
- GRB 030227, possible optical counterpart of XMM-Newton source
- GRB030227 - faint tentative OT candidate
- GRB 030226, optical observations
- GRB030227: Kiso optical observations
- GRB 030227: Kyoto optical observation
- GRB 030226, optical light curve
- GRB 030226 spectroscopy
- Possible break in the GRB 030226 light curve
- GRB 030226 : Predicted light curve
- IPN triangulation of GRB030225 (annulus)
- GRB 030226: Confirmed decay index
- GRB030226: ESI spectroscopy
- GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
- GRB 030226 simultaneous optical observations
- Two absorption systems in GRB 030226
- GRB 030226, optical observations
- GRB 030226 Optical Spectra and R,I,z' Imaging
- GRB 030226, optical observations
- GRB 030226: Optical afterglow
- GRB 030217: Optical Observations at 4, 5, and 6 Days
- IPN triangulation of GRB030223 (annulus)
- IPN triangulation of GRB030220 (annulus)
- GRB: Non-Referencing of GCN Circulars.
- IPN triangulation of GRB030218 (annulus)
- IPN triangulation of GRB030217 (small error box)
- IPN triangulation of GRB030215C (annulus)
- IPN triangulation of GRB030217 (annulus)
- IPN triangulation of GRB030216 (annulus)
- IPN triangulation of GRB030215A and GRB030215B (annuli)
- GRB030115, WSRT radio observations - correction to GCN 1864
- GRB 030131: marginal optical detection
- GRB030115, WSRT radio observations
- IPN triangulation of GRB030206 (annulus)
- IPN triangulation of GRB030208 (annulus)