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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. GRB 010222, Optical Observations
  2. GRB010220 optical obsercations
  3. GRB010222 - Optical observation
  4. GRB 010222: High-Resolution Keck Spectroscopy
  5. GRB010222: Optical observation and decay
  6. GRB 010214, I-band data
  7. Sub-millimeter Excess/GRB 010222
  8. GRB 010222
  9. GRB 010222 HST/Chandra TOO
  10. GRB 010222
  11. GRB010222 further R-band photometry
  12. GRB010222: R-band data
  13. GRB010222 Optical observations
  14. GRB 010222: Keck Spectroscopy
  15. GRB010214, field photometry
  16. GRB010222, field photometry
  17. GRB010222 further R-band photometry
  18. GRB010222, possible increase of optical decay slope
  19. GRB 010222 Kyoto optical observation
  20. GRB010222: fading behavior
  21. GRB 010222 BV optical observations
  22. GRB010220, Optical Observations
  23. GRB010222 R-BAND OBSERVATION
  24. GRB 010220: Near-IR Observations
  25. GRB010214 follow-up from Hanle
  26. GRB 010222: Near-IR Observations
  27. GRB 010222: Optical Observations
  28. GRB 010222, Decay Slope Confirmed
  29. GRB010222: Another absorption line system
  30. GRB010222: Optical decay slope
  31. GRB 010214, Optical Observations
  32. GRB010222: Sub-millimeter detection
  33. GRB010222: R-band fading behavior
  34. GRB010222: Optical Observations
  35. GRB010222, radio observations
  36. GRB010222, optical observations
  37. GRB010222: BeppoSAX/NFI Observations
  38. Redshift of the Optical Transient of GRB010222
  39. GRB010214B,Gamma Ray Observations
  40. GRB010222: possible optical counterpart
  41. GRB010222
  42. GRB010222
  43. GRB010222: BeppoSAX refined position
  44. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  45. GRB010220, Radio and Optical Observations
  46. GRB 010220, simultaneous optical observations
  47. GRB010220: BeppoSAX WFC and GRBM preliminary data
  48. GRB010214, candidate optical afterglow
  49. GRB010214, optical observations
  50. BeppoSAX GRB010220: refined position
  51. BeppoSAX ALERT: GRB010220
  52. GRB010214: BeppoSAX WFC and GRBM preliminary data
  53. GRB 010214: X-Ray afterglow
  54. GRB 010214, Optical Observations
  55. GRB 010214 optical observation
  56. GRB010213, Radio Observations
  57. GRB010213 Optical Observation
  58. GRB010213, Radio Observations
  59. J-Band Observation of GRB 010214.
  60. GRB010214, Radio Observations
  61. GRB010214, optical observations
  62. GRB010213, optical observations
  63. GRB010213, Near-IR observations
  64. Possible InfraRed Transient of GRB 010214.
  65. GRB010214 Optical Observation
  66. GRB010214: BeppoSAX/NFI Observations
  67. GRB010213 (HETE) TAROT observations
  68. GRB 010214, optical observations
  69. GRB010213 detected by HETE
  70. GRB010214 refined WFC position
  71. BeppoSAX ALERT: GRB010214
  72. IPN Status Report
  73. HETE Status
  74. GRB010126 opt. obs.
  75. IPN/RXTE TRIANGULATION OF GRB010126
  76. GRB010126: CONCAM crude optical limits during GRB
  77. GRB010126, TNG R-band observations
  78. GRB010126 Optical Observations
  79. GRB010126 optical observations
  80. GRB010126: Optical observations
  81. IPN TRIANGULATION OF GRB010126
  82. IPN/RXTE TRIANGULATION OF GRB010126
  83. GRB 010119, optical observations
  84. GRB010119: Optical observations
  85. Optical Observations of GRB 001018 at Keck
  86. GRB010119, Radio observations
  87. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  88. Optical observations of GRB 001018 with JCAM
  89. IPN TRIANGULATION OF GRB010115
  90. IPN TRIANGULATION OF GRB010109
  91. IPN TRIANGULATION OF GRB010109
  92. GRB010103, optical observations
  93. IPN triangulation of GRB010104
  94. IPN triangulation of GRB010103
  95. GRB 001204: Ks observations
  96. H band observation of GRB 001212
  97. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  98. IPN triangulation of GRB001219
  99. GRB 001212 Optical Observation
  100. GRB 001212 Optical Observation

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