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"4022 results found.
- LIGO/Virgo G184098: SkyMapper observations
- LIGO/Virgo G184098: TAROT network optical observations
- LIGO/Virgo G184098: La Silla - QUEST Followup
- LIGO/Virgo G184098: Swift follow-up observations
- LIGO/Virgo G184098: MWA Followup
- LIGO/Virgo G184098: DESGW followup program
- LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
- LIGO/Virgo observing run 1 (O1) starts 2015-09-18 15:00 UTC
- LIGO/Virgo G184098: Keck II DEIMOS Spectra of iPTF Optical Candidates
- LIGO/Virgo G184098: Nearby Galaxies in Error Circle
- LIGO/Virgo G184098: Fermi-GBM ground-based follow-up
- LIGO/Virgo G184098: Observations from the TOROS collaboration
- LIGO/Virgo G184098: iPTF Optical Transient Candidates
- LIGO/Virgo G184098: VST-ESO PARANAL observations
- LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
- Instructions for reporting follow-up observations related to LIGO/Virgo G184098
- LIGO/Virgo G184098: observations by MASTER
- LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
- LIGO/Virgo G184098: Swift follow-up observations
- LIGO/Virgo G184098: Burst candidate in LIGO engineering run data
- GRB 150906B: theoretical estimation of redshift and isotropic energy
- Short GRB 150906B: proximity to NGC 3313 galaxy group
- IPN Triangulation of GRB 150819B (short / very intense)
- V404 Cyg: Fermi GBM observations
- Disreqard the recent cluster of Swift-related GCN Circulars
- GRB 150430A: Swift detection of a burst
- Fermi GBM Observations of Magnetar 4U 0142+61
- IPN Triangulation of GRB 150220A
- Fermi GBM Observations of SGR 1935+2154
- IPN Triangulation of GRB 150127B
- IPN Triangulation of GRB 150127A
- IPN triangulation of GRB 150118C (short/hard)
- IPN Triangulation of GRB 141215A (long/intense)
- IPN Triangulation of GRB 141202A (short/hard)
- GRB 141121A: three epochs of SAO RAS optical observations
- IPN Triangulation of GRB 140901A (short/hard/very intense)
- IPN triangulation of GRB 140801A (Fermi trigger 428612396)
- GRB 140610A: Swift detection of a burst
- IPN Triangulation of GRB 131209A
- IPN Triangulation of GRB 131126A (short/hard)
- IPN Triangulation of GRB 131125A (short/hard)
- GRB 131108A: AGILE/GRID observation
- Swift Operations in the event of a US Government shutdown
- US Government shutdown may impact GRB operation of GCN
- GRB 130822A: nearby galaxy redshifts
- IPN Triangulation of long GRB 120916A
- Corrections to the Fermi-LAT upper limits for GRB 120807A, 120908A, 120909A, and 120911A
- Swift starts a new program to find fainter transients
- IPN Triangulation of GRB 120328B (long/intense)
- GRB 120316A: Fermi-GBM and Fermi-LAT Observations
- IPN Triangulation of GRB 120226A
- All GCN Circulars available in a tarfile for data mining
- IPN triangulation of GRB110825A (very intense, long-duration)
- Fermi-GBM data processing and delivery
- GRB 100805A: Xinglong TNT optical observation
- Swift-BAT trigger 421695 is likely not astrophysical
- IPN triangulation of GRB100324B
- GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
- Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts
- First GLAST Burst Monitor GRB Circulars
- Reactivation of SGR 1627-41
- procesure for GRB Circular
- GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
- Swift-XRT improved positions, and new redshift limits.
- GRB 080121 position was incorrect
- Disregard the "GRB 071126" position
- Swift autonomous slewing re-enabled
- GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
- GRB 071003: Possible rebrightening
- Update on Swift Status
- Swift Status and XRT Calibration Uncertainties
- GCN Swift XRT update position notices and enhanced position circulars
- Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
- GRB 070125: Break in Optical Decay
- GRB 060929: Further XRT Refined Analysis
- test of new software, grb
- GRB 060927: Early color
- GRB 060526: Break in X-ray light curve
- GRB 051221: Improved astrometry of the IR counterpart
- GRB051105: optical observations
- GRB 051105a: MDM Observations
- Swift-BAT trigger 147918 is not a real GRB
- GRB 050721A: Swift-BAT refined analysis
- Swift BAT Trigger 146986 is SWIFT J1753.5-0127
- Retraction of three Swift GRB triggers
- GRB 050319: ROTSE-III Refined Analysis
- SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
- GRB041006: MASTER optical observations
- IBAS GRB Alerts 1978-1980
- IPN Summary of SGR1806-20 Activity in 2004
- GRB and XRF on April 27, 2004. Detection by Konus-Wind and Helicon (Coronas-F)
- On Line Availability of Archival HETE Fregate Data and Lightcurves
- GRB 040223 XMM-Newton observation ...
- Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
- XRF030723 (=H2777): Second Epoch Magellan Observations
- GRBlog: Compilation of all GCN Circ. data
- GRB 030329 and SN 2003dh
- GRB030329: multiple re-brightening phases
- GRB: Non-Referencing of GCN Circulars.
- GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)