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"

35955 results found.

  1. GRB010214B,Gamma Ray Observations
  2. GRB010222
  3. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  4. GRB 010220, simultaneous optical observations
  5. GRB010220: BeppoSAX WFC and GRBM preliminary data
  6. BeppoSAX ALERT: GRB010220
  7. GRB010214: BeppoSAX WFC and GRBM preliminary data
  8. GRB 010214: X-Ray afterglow
  9. GRB 010214, Optical Observations
  10. GRB 010214 optical observation
  11. GRB010213 Optical Observation
  12. J-Band Observation of GRB 010214.
  13. GRB010213, Near-IR observations
  14. Possible InfraRed Transient of GRB 010214.
  15. GRB010214 Optical Observation
  16. GRB010214: BeppoSAX/NFI Observations
  17. GRB010213 (HETE) TAROT observations
  18. GRB 010214, optical observations
  19. BeppoSAX ALERT: GRB010214
  20. IPN Status Report
  21. HETE Status
  22. GRB010126 opt. obs.
  23. IPN/RXTE TRIANGULATION OF GRB010126
  24. GRB010126: CONCAM crude optical limits during GRB
  25. GRB010126, TNG R-band observations
  26. IPN TRIANGULATION OF GRB010126
  27. IPN/RXTE TRIANGULATION OF GRB010126
  28. GRB 010119, optical observations
  29. GRB010119: Optical observations
  30. Optical Observations of GRB 001018 at Keck
  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. GRB010103, optical observations
  36. IPN triangulation of GRB010104
  37. IPN triangulation of GRB010103
  38. GRB 001204: Ks observations
  39. H band observation of GRB 001212
  40. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  41. IPN triangulation of GRB001219
  42. GRB 001212 Optical Observation
  43. GRB 001212 Optical Observation
  44. GRB 001212 optical observation
  45. GRB 001212 possible OA in 2MASS
  46. GRB 001212 possible OA
  47. IPN triangulation of GRB001212
  48. Confirmation of IPN position for GRB001204
  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. IPN triangulation of GRB001120
  56. Optical/NIR observations of GRB001109
  57. GRB 001109: deep JHK upper limits
  58. GRB 001109 X-ray afterglow with BeppoSAX
  59. GRB001109: Optical observations
  60. GRB001109: BeppoSAX/NFI Observations
  61. GRB001109, R-band optical observations
  62. GRB001109, Radio observations
  63. BeppoSAX ALERT: GRB001109
  64. GRB001105 BVRI field photometry correction
  65. GRB001105, BVRI field photometry
  66. GRB 001105, R-band observation
  67. IPN TRIANGULATION OF GRB001105
  68. GRB 001025B, Optical obervations
  69. GRB 991208: HST Imaging of the Host Galaxy
  70. GRB000926: R-image of the host galaxy
  71. GRB 001025B, I-band observations
  72. GRB 001025 Optical Observations
  73. GRB 001025A, optical observation
  74. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  75. IPN triangulation of GRB001025
  76. ASM Localization of GRB 001025
  77. GRB001007, Radio observations
  78. IPN TRIANGULATION OF GRB001020
  79. GRB001019, Optical Observations
  80. GRB 001018, Possible Radio Afterglow
  81. GRB001018, Gamma Ray Observations
  82. IPN TRIANGULATION OF GRB001019
  83. IPN TRIANGULATION OF GRB001018
  84. IPN TRIANGULATION OF GRB 001017
  85. GRB 000926: Improved Absorber Redshift
  86. V,R,I band observations of GRB000926
  87. The Likely Optical/Infrared Afterglow of GRB 001011
  88. HETE positions added to GCN
  89. BeppoSAX ALERT: GRB001011
  90. GRB 001007, BVR-band observations
  91. GRB000926 - Amateur Optical Observations
  92. CONCAM null result on GRB001005
  93. IPN triangulation of GRB001007
  94. GRB 000926 : the host galaxy
  95. IPN triangulation of GRB001005
  96. GRB 000926 Chandra Observation
  97. IPN triangulation of GRB 001004
  98. Public availability of BeppoSAX data of GRB000926
  99. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  100. GRB 000926, Optical Decay

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