Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. See news and announcements

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').
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"

2708 results found.

  1. GRB 021004: Optical Observations
  2. XRF020903: TNG and Asiago photometry
  3. XRF 020903: R band observations
  4. XRF 020903: Archival Optical Images
  5. IPN triangulation of GRB020926 (two large error boxes)
  6. IPN triangulation of GRB020923 (two error boxes)
  7. IPN annulus for GRB020923
  8. IPN triangulation of GRB020914B
  9. Improved IPN position for GRB020918 (two large error boxes)
  10. IPN annulus for GRB020914B
  11. IPN triangulation of GRB020911 (2 large error boxes)
  12. IPN triangulation of GRB020914 - clarification and additional information
  13. IPN triangulation of GRB020910
  14. IPN GCN Circulars now to be issued without restriction
  15. GRB 020813 : HST observations
  16. GRB020813: Magellan BVRI Photometry
  17. GRB020813: High-Resolution Optical Observations
  18. GRB020813: optical observations; possible host galaxy
  19. GRB020812: optical observations
  20. IPN triangulation of GRB020813
  21. GRB020812: possible afterglow candidate
  22. GRB020812: possible afterglow candidate
  23. GRB 020813 Afterglow Observations; Possible break
  24. GRB 020410: Discovery of Probable OT by HST
  25. IPN triangulation of GRB020706
  26. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  27. Fading Optical Source in the Field of GRB020531
  28. GRB 020531, simultaneous optical observations
  29. GRB020531 Optical observations with TAROT
  30. GRB020531 Optical observations with TAROT
  31. IPN triangulation of GRB020604
  32. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  33. IPN triangulation of GRB020603 (possible short/hard GRB)
  34. GRB 020531 optical observations with TAROT
  35. IPN detection of possible bursts from SGR1806-20
  36. GRB020427 BeppoSAX NFI Observation
  37. GRB020405: VLT observations of the OT environment
  38. GRB020405: predicted break
  39. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  40. BeppoSAX ALERT: possible GRB020411
  41. GRB020406(?), optical observations
  42. GRB020410, optical observations
  43. BeppoSAX ALERT: possible GRB020410
  44. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  45. GRB 020321, Radio Observations
  46. GRB020321: BeppoSAX/NFI Observations
  47. GRB 020317: Optical observations
  48. GRB 011121: HST Observations reveal an intermediate-time multicolor
  49. GRB011121, possible supernova association
  50. GRB020127: Further VLA Observations of Possible Counterparts
  51. GRB020127: Palomar and VLA Observations of Possible Counterparts
  52. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  53. SN 2002ap (SN/GRB?)
  54. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  55. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  56. GRB 020124 Optical Observations
  57. GRB optical counterpart candidate in GCN 1217 is M dwarf
  58. Possible optical counterpart to a GRB
  59. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  60. GRB 011130: Magellan spectroscopy
  61. GRB011130, optical observations
  62. GRB 011121: J-band observations
  63. GRB 011121: HST Scheduled
  64. GRB011121: fainter still
  65. GRB011121: continued decay
  66. GRB011121: possible redshift, continued decay
  67. GRB011121: fading behavior
  68. GRB011121: possible optical counterpart
  69. GRB 011030 I-band Observation
  70. GRB 011030, WSRT radio observations
  71. BeppoSAX ALERT: Possible X-ray rich GRB011030
  72. GRB 010921: Possible supernova component
  73. GRB010921: Spectroscopy of the Host Galaxy
  74. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  75. IPN triangulation of GRB010921 (=H1761)
  76. GCN and HETE status
  77. GRB010629: Optical Observations
  78. Possible burst from SGR1806-20
  79. IPN triangulation of GRB010613
  80. HETE Fully-Automated GCN Notices
  81. GRB010214, optical observations
  82. SGR1900+14
  83. Possible precursor to the SGR1900+14 giant burst
  84. Further Optical Observations of GRB 010324
  85. GRB 010222, Optical Observations
  86. Sub-millimeter Excess/GRB 010222
  87. GRB010222: R-band data
  88. GRB010222, possible increase of optical decay slope
  89. GRB010222: Optical Observations
  90. GRB010222: possible optical counterpart
  91. GRB010222
  92. GRB 010214, Optical Observations
  93. GRB010214, Radio Observations
  94. GRB010214, optical observations
  95. Possible InfraRed Transient of GRB 010214.
  96. GRB010126 optical observations
  97. IPN TRIANGULATION OF GRB010126
  98. GRB 001212 Optical Observation
  99. GRB 001212 possible OA in 2MASS
  100. GRB 001212 possible OA

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov