Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
Circulars over Kafka event name backfill. 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"
  1. GRB010222: Sub-millimeter detection
  2. GRB010222: R-band fading behavior
  3. GRB010222: Optical Observations
  4. GRB010222, radio observations
  5. GRB010222, optical observations
  6. GRB010222: BeppoSAX/NFI Observations
  7. Redshift of the Optical Transient of GRB010222
  8. GRB010214B,Gamma Ray Observations
  9. GRB010222: possible optical counterpart
  10. GRB010222
  11. GRB010222
  12. GRB010222: BeppoSAX refined position
  13. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  14. GRB010220, Radio and Optical Observations
  15. GRB 010220, simultaneous optical observations
  16. GRB010220: BeppoSAX WFC and GRBM preliminary data
  17. GRB010214, candidate optical afterglow
  18. GRB010214, optical observations
  19. BeppoSAX GRB010220: refined position
  20. BeppoSAX ALERT: GRB010220
  21. GRB010214: BeppoSAX WFC and GRBM preliminary data
  22. GRB 010214: X-Ray afterglow
  23. GRB 010214, Optical Observations
  24. GRB 010214 optical observation
  25. GRB010213, Radio Observations
  26. GRB010213 Optical Observation
  27. GRB010213, Radio Observations
  28. J-Band Observation of GRB 010214.
  29. GRB010214, Radio Observations
  30. GRB010214, optical observations
  31. GRB010213, optical observations
  32. GRB010213, Near-IR observations
  33. Possible InfraRed Transient of GRB 010214.
  34. GRB010214 Optical Observation
  35. GRB010214: BeppoSAX/NFI Observations
  36. GRB010213 (HETE) TAROT observations
  37. GRB 010214, optical observations
  38. GRB010213 detected by HETE
  39. GRB010214 refined WFC position
  40. BeppoSAX ALERT: GRB010214
  41. IPN Status Report
  42. HETE Status
  43. GRB010126 opt. obs.
  44. IPN/RXTE TRIANGULATION OF GRB010126
  45. GRB010126: CONCAM crude optical limits during GRB
  46. GRB010126, TNG R-band observations
  47. GRB010126 Optical Observations
  48. GRB010126 optical observations
  49. GRB010126: Optical observations
  50. IPN TRIANGULATION OF GRB010126
  51. IPN/RXTE TRIANGULATION OF GRB010126
  52. GRB 010119, optical observations
  53. GRB010119: Optical observations
  54. Optical Observations of GRB 001018 at Keck
  55. GRB010119, Radio observations
  56. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  57. Optical observations of GRB 001018 with JCAM
  58. IPN TRIANGULATION OF GRB010115
  59. IPN TRIANGULATION OF GRB010109
  60. IPN TRIANGULATION OF GRB010109
  61. GRB010103, optical observations
  62. IPN triangulation of GRB010104
  63. IPN triangulation of GRB010103
  64. GRB 001204: Ks observations
  65. H band observation of GRB 001212
  66. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  67. IPN triangulation of GRB001219
  68. GRB 001212 Optical Observation
  69. GRB 001212 Optical Observation
  70. GRB 001212 optical observation
  71. GRB 001212 possible OA in 2MASS
  72. GRB 001212 possible OA
  73. IPN triangulation of GRB001212
  74. GRB001204: Optical observations
  75. Confirmation of IPN position for GRB001204
  76. GRB001204, Radio observations
  77. IPN triangulation of GRB001204 (short/hard)
  78. GRB 001105, further optical observations
  79. GRB001120: Gunn-i observations
  80. GRB001120: Optical observations
  81. GRB001109, optical observations
  82. GRB001120, optical observations
  83. WSRT 4.8 GHz observations of GRB001109
  84. IPN triangulation of GRB001120
  85. Optical/NIR observations of GRB001109
  86. GRB 001109: deep JHK upper limits
  87. GRB 001109 X-ray afterglow with BeppoSAX
  88. CORRECTION to XMM-Newton observation of GRB001025
  89. GRB001109: Optical observations
  90. GRB001109: BeppoSAX/NFI Observations
  91. GRB001109, R-band optical observations
  92. GRB001109, Radio observations
  93. GRB001109: BeppoSAX refined WFC position
  94. BeppoSAX ALERT: GRB001109
  95. GRB001105 BVRI field photometry correction
  96. GRB001105, BVRI field photometry
  97. GRB 001105, R-band observation
  98. IPN TRIANGULATION OF GRB001105
  99. GRB 001025B, Optical obervations
  100. GRB 991208: HST Imaging of the Host Galaxy

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