Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
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"

25724 results found.

  1. GRB 021004 radio observation
  2. GRB 021004: Optical Photometry at 1.5 Days
  3. GRB021004, BVRcIc field photometry
  4. GRB021004: Optical Spectroscopy
  5. GRB 021004 radio search
  6. XRF020903, BVRI field photometry
  7. XRF020903: TNG and Asiago photometry
  8. GRB 020903: Optical observations at RIKEN
  9. XRF 020903: Correction to GCN 1560
  10. XRF 020903: VRI observations
  11. XRF 020903: R band observations
  12. XRF 020903: Archival Optical Images
  13. Radio Observations of XRF 020903: The Missing Link
  14. XRF 020903: Supernova
  15. IPN triangulation of GRB020923 (two error boxes)
  16. IPN triangulation of GRB020914B
  17. IPN triangulation of GRB020911 (2 large error boxes)
  18. GRB 020305: HST/STIS observations
  19. Confirmation of IPN error box for GRB020910
  20. IPN triangulation of GRB020910
  21. IPN GCN Circulars now to be issued without restriction
  22. Single IPN error box for GRB020904
  23. XRF 020903: optical observation at Kyoto
  24. GRB020322 : HST/STIS observations
  25. XRF 020903: Optical observations
  26. IPN triangulation of GRB020904
  27. INTEGRAL GRBs added to GCN
  28. SGR1900+14 burst localized by HETE
  29. GRB020813: High-resolution optical spectroscopy
  30. GRB020812: negative optical observations
  31. GRB 020812: optical observation at Kyoto University
  32. Second epoch K band imaging of GRB 020819
  33. GRB 020813 : HST observations
  34. GRB 020812: early time optical observation at Ouda Station
  35. GRB020813: Magellan BVRI Photometry
  36. GRB 020819: Optical observations
  37. K band observation of GRB 020819
  38. GRB020813: optical and NIR observations
  39. GRB020813: Fading X-ray Afterglow Observed with Chandra
  40. GRB020813, UBVRI field calibration
  41. GRB020812: NIR observations
  42. Polarimetry of GRB020813: evidence for variability
  43. GRB020813 IRAM millimeter observations
  44. GRB020812: optical observations
  45. GRB020813: High-Resolution Optical Observations
  46. GRB 020812: optical observation at Bisei
  47. GRB020813: Early Time Magnitude
  48. Millimeter observation of GRB 020813
  49. GRB020812: optical observations
  50. GRB 020813 : KISO multiband optical observations
  51. GRB020813, optical observations
  52. IPN error box for GRB020813
  53. GRB020813, astrometric position
  54. Spectropolarimetry of GRB 020813
  55. GRB 020812 optical observation
  56. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  57. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  58. HST Imaging of the Host of GRB 011121
  59. GRB020801, optical afterglow candidate
  60. GRB020331: Late-time Optical Light Curve (re-submission)
  61. GRB020331: Late-time Optical Light Curve
  62. IPN triangulation of GRB020714
  63. IPN triangulation of GRB020715 (=GRB150702)
  64. IPN triangulation of GRB020714
  65. IPN triangulation of GRB150702
  66. GRB 020410: Discovery of Probable OT by HST
  67. GRB 020124, HST observations of the fading afterglow
  68. IPN triangulation of GRB020708
  69. IPN triangulation of GRB020708
  70. Correction to IPN error box for GRB020706
  71. IPN triangulation of GRB020706
  72. GRB 020705: Optical observations
  73. GRB 020625, optical observations
  74. GRB 020625: Optical observations
  75. GRB 020531: optical photometry of Chandra sources
  76. GRB020625 (=H2081): A Long Burst Localized by HETE
  77. The Probable Host Galaxy of GRB/XRF 020427
  78. GRB/XRF 020427, detection of an underlying system with the VLT
  79. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  80. AXP 1E2259+586 optical observations
  81. Fading Optical Source in the Field of GRB020531
  82. GRB 020531, INT+WFC deep optical upper limits
  83. SGR-like Bursts from the AXP 1E 2259+586
  84. GRB020405: polarimetric observations
  85. GRB 020531, simultaneous optical observations
  86. GRB 020531/Candidate Redshift
  87. GRB020531: Detection of Candidate Host Galaxy
  88. GRB020531: Second epoch Chandra observations
  89. GRB020604, optical observations
  90. GRB020604, BVRcIc field photometry
  91. GRB020603, BVRcIc field observations
  92. GRB020531, BVRcIc field photometry
  93. GRB020531 Optical Observations
  94. GRB020531: Observations with the Chandra X-ray Observatory
  95. GRB020531, optical observations
  96. GRB020531: optical observations
  97. GRB020531(=H2042): Optical Observations
  98. GRB020531(=H2042): Optical Observations
  99. GRB020531: Optical observations
  100. GRB020531(=H2042): A Short, Hard Burst Localized by HETE

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