Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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. GRB010214, Radio Observations
  2. GRB010214, optical observations
  3. GRB010213, optical observations
  4. GRB010213, Near-IR observations
  5. Possible InfraRed Transient of GRB 010214.
  6. GRB010214 Optical Observation
  7. GRB010214: BeppoSAX/NFI Observations
  8. GRB010213 (HETE) TAROT observations
  9. GRB 010214, optical observations
  10. GRB010213 detected by HETE
  11. GRB010214 refined WFC position
  12. BeppoSAX ALERT: GRB010214
  13. IPN Status Report
  14. HETE Status
  15. GRB010126 opt. obs.
  16. IPN/RXTE TRIANGULATION OF GRB010126
  17. GRB010126: CONCAM crude optical limits during GRB
  18. GRB010126, TNG R-band observations
  19. GRB010126 Optical Observations
  20. GRB010126 optical observations
  21. GRB010126: Optical observations
  22. IPN TRIANGULATION OF GRB010126
  23. IPN/RXTE TRIANGULATION OF GRB010126
  24. GRB 010119, optical observations
  25. GRB010119: Optical observations
  26. Optical Observations of GRB 001018 at Keck
  27. GRB010119, Radio observations
  28. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  29. Optical observations of GRB 001018 with JCAM
  30. IPN TRIANGULATION OF GRB010115
  31. IPN TRIANGULATION OF GRB010109
  32. IPN TRIANGULATION OF GRB010109
  33. GRB010103, optical observations
  34. IPN triangulation of GRB010104
  35. IPN triangulation of GRB010103
  36. GRB 001204: Ks observations
  37. H band observation of GRB 001212
  38. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  39. IPN triangulation of GRB001219
  40. GRB 001212 Optical Observation
  41. GRB 001212 Optical Observation
  42. GRB 001212 optical observation
  43. GRB 001212 possible OA in 2MASS
  44. GRB 001212 possible OA
  45. IPN triangulation of GRB001212
  46. GRB001204: Optical observations
  47. Confirmation of IPN position for GRB001204
  48. GRB001204, Radio observations
  49. IPN triangulation of GRB001204 (short/hard)
  50. GRB 001105, further optical observations
  51. GRB001120: Gunn-i observations
  52. GRB001120: Optical observations
  53. GRB001109, optical observations
  54. GRB001120, optical observations
  55. WSRT 4.8 GHz observations of GRB001109
  56. IPN triangulation of GRB001120
  57. Optical/NIR observations of GRB001109
  58. GRB 001109: deep JHK upper limits
  59. GRB 001109 X-ray afterglow with BeppoSAX
  60. CORRECTION to XMM-Newton observation of GRB001025
  61. GRB001109: Optical observations
  62. GRB001109: BeppoSAX/NFI Observations
  63. GRB001109, R-band optical observations
  64. GRB001109, Radio observations
  65. GRB001109: BeppoSAX refined WFC position
  66. BeppoSAX ALERT: GRB001109
  67. GRB001105 BVRI field photometry correction
  68. GRB001105, BVRI field photometry
  69. GRB 001105, R-band observation
  70. IPN TRIANGULATION OF GRB001105
  71. GRB 001025B, Optical obervations
  72. GRB 991208: HST Imaging of the Host Galaxy
  73. GRB000926: R-image of the host galaxy
  74. GRB 001025B, I-band observations
  75. XMM-Newton observation of GRB001025
  76. GRB001025B, Radio observations
  77. GRB 001025 Optical Observations
  78. GRB 001025A, optical observation
  79. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  80. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  81. IPN triangulation of GRB001025
  82. GRB001007: Optical observations
  83. ASM Localization of GRB 001025
  84. GRB001007, Radio observations
  85. IPN TRIANGULATION OF GRB001020
  86. GRB001019, Optical Observations
  87. GRB 001018, Possible Radio Afterglow
  88. GRB001018, Gamma Ray Observations
  89. IPN TRIANGULATION OF GRB001019
  90. CORRECTION TO PEAK FLUX OF GRB001018
  91. IPN TRIANGULATION OF GRB001018
  92. IPN TRIANGULATION OF GRB 001017
  93. GRB 000926: Improved Absorber Redshift
  94. V,R,I band observations of GRB000926
  95. The Likely Optical/Infrared Afterglow of GRB 001011
  96. HETE positions added to GCN
  97. GRB001011 BeppoSAX/WFC refined position
  98. BeppoSAX ALERT: GRB001011
  99. GRB 001007, BVR-band observations
  100. GRB000926 - Amateur Optical Observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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