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

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