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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. IPN TRIANGULATION OF GRB010324
  2. GRB990705, VLT-FORS1 observations of the host galaxy
  3. GRB010222, late-time optical observation
  4. Support extension to the BeppoSAX mission
  5. GRB 010222 - HEGRA GeV/TeV Observations
  6. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  7. GRB010222: Chandra X-ray Observatory Observation
  8. GRB010222: Sub-millimeter vanishing act
  9. GRB010222 - Optical observation
  10. GRB 010222, Optical Observations
  11. GRB010220 optical obsercations
  12. GRB010222 - Optical observation
  13. GRB 010222: High-Resolution Keck Spectroscopy
  14. GRB010222: Optical observation and decay
  15. GRB 010214, I-band data
  16. Sub-millimeter Excess/GRB 010222
  17. GRB 010222
  18. GRB 010222 HST/Chandra TOO
  19. GRB 010222
  20. GRB010222 further R-band photometry
  21. GRB010222: R-band data
  22. GRB010222 Optical observations
  23. GRB 010222: Keck Spectroscopy
  24. GRB010214, field photometry
  25. GRB010222, field photometry
  26. GRB010222 further R-band photometry
  27. GRB010222, possible increase of optical decay slope
  28. GRB 010222 Kyoto optical observation
  29. GRB010222: fading behavior
  30. GRB 010222 BV optical observations
  31. GRB010220, Optical Observations
  32. GRB010222 R-BAND OBSERVATION
  33. GRB 010220: Near-IR Observations
  34. GRB010214 follow-up from Hanle
  35. GRB 010222: Near-IR Observations
  36. GRB 010222: Optical Observations
  37. GRB 010222, Decay Slope Confirmed
  38. GRB010222: Another absorption line system
  39. GRB010222: Optical decay slope
  40. GRB 010214, Optical Observations
  41. GRB010222: Sub-millimeter detection
  42. GRB010222: R-band fading behavior
  43. GRB010222: Optical Observations
  44. GRB010222, radio observations
  45. GRB010222, optical observations
  46. GRB010222: BeppoSAX/NFI Observations
  47. Redshift of the Optical Transient of GRB010222
  48. GRB010214B,Gamma Ray Observations
  49. GRB010222: possible optical counterpart
  50. GRB010222
  51. GRB010222
  52. GRB010222: BeppoSAX refined position
  53. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  54. GRB010220, Radio and Optical Observations
  55. GRB 010220, simultaneous optical observations
  56. GRB010220: BeppoSAX WFC and GRBM preliminary data
  57. GRB010214, candidate optical afterglow
  58. GRB010214, optical observations
  59. BeppoSAX GRB010220: refined position
  60. BeppoSAX ALERT: GRB010220
  61. GRB010214: BeppoSAX WFC and GRBM preliminary data
  62. GRB 010214: X-Ray afterglow
  63. GRB 010214, Optical Observations
  64. GRB 010214 optical observation
  65. GRB010213, Radio Observations
  66. GRB010213 Optical Observation
  67. GRB010213, Radio Observations
  68. J-Band Observation of GRB 010214.
  69. GRB010214, Radio Observations
  70. GRB010214, optical observations
  71. GRB010213, optical observations
  72. GRB010213, Near-IR observations
  73. Possible InfraRed Transient of GRB 010214.
  74. GRB010214 Optical Observation
  75. GRB010214: BeppoSAX/NFI Observations
  76. GRB010213 (HETE) TAROT observations
  77. GRB 010214, optical observations
  78. GRB010213 detected by HETE
  79. GRB010214 refined WFC position
  80. BeppoSAX ALERT: GRB010214
  81. IPN Status Report
  82. HETE Status
  83. GRB010126 opt. obs.
  84. IPN/RXTE TRIANGULATION OF GRB010126
  85. GRB010126: CONCAM crude optical limits during GRB
  86. GRB010126, TNG R-band observations
  87. GRB010126 Optical Observations
  88. GRB010126 optical observations
  89. GRB010126: Optical observations
  90. IPN TRIANGULATION OF GRB010126
  91. IPN/RXTE TRIANGULATION OF GRB010126
  92. GRB 010119, optical observations
  93. GRB010119: Optical observations
  94. Optical Observations of GRB 001018 at Keck
  95. GRB010119, Radio observations
  96. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  97. Optical observations of GRB 001018 with JCAM
  98. IPN TRIANGULATION OF GRB010115
  99. IPN TRIANGULATION OF GRB010109
  100. IPN TRIANGULATION OF GRB010109

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