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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"

41193 results found.

  1. Support extension to the BeppoSAX mission
  2. GRB 010222 - HEGRA GeV/TeV Observations
  3. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  4. GRB010222: Chandra X-ray Observatory Observation
  5. GRB010222: Sub-millimeter vanishing act
  6. GRB010222 - Optical observation
  7. GRB 010222, Optical Observations
  8. GRB010220 optical obsercations
  9. GRB010222 - Optical observation
  10. GRB 010222: High-Resolution Keck Spectroscopy
  11. GRB010222: Optical observation and decay
  12. GRB 010214, I-band data
  13. Sub-millimeter Excess/GRB 010222
  14. GRB 010222
  15. GRB 010222 HST/Chandra TOO
  16. GRB 010222
  17. GRB010222 further R-band photometry
  18. GRB010222: R-band data
  19. GRB010222 Optical observations
  20. GRB 010222: Keck Spectroscopy
  21. GRB010214, field photometry
  22. GRB010222, field photometry
  23. GRB010222 further R-band photometry
  24. GRB010222, possible increase of optical decay slope
  25. GRB 010222 Kyoto optical observation
  26. GRB010222: fading behavior
  27. GRB 010222 BV optical observations
  28. GRB010220, Optical Observations
  29. GRB010222 R-BAND OBSERVATION
  30. GRB 010220: Near-IR Observations
  31. GRB010214 follow-up from Hanle
  32. GRB 010222: Near-IR Observations
  33. GRB 010222: Optical Observations
  34. GRB 010222, Decay Slope Confirmed
  35. GRB010222: Another absorption line system
  36. GRB010222: Optical decay slope
  37. GRB 010214, Optical Observations
  38. GRB010222: Sub-millimeter detection
  39. GRB010222: R-band fading behavior
  40. GRB010222: Optical Observations
  41. GRB010222, radio observations
  42. GRB010222, optical observations
  43. GRB010222: BeppoSAX/NFI Observations
  44. Redshift of the Optical Transient of GRB010222
  45. GRB010222: possible optical counterpart
  46. GRB010222
  47. GRB010220, Radio and Optical Observations
  48. GRB 010220, simultaneous optical observations
  49. GRB010220: BeppoSAX WFC and GRBM preliminary data
  50. GRB010214, candidate optical afterglow
  51. GRB010214, optical observations
  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. GRB010213 (HETE) TAROT observations
  67. GRB 010214, optical observations
  68. GRB010213 detected by HETE
  69. HETE Status
  70. GRB010126 opt. obs.
  71. IPN/RXTE TRIANGULATION OF GRB010126
  72. GRB010126: CONCAM crude optical limits during GRB
  73. GRB010126, TNG R-band observations
  74. GRB010126 Optical Observations
  75. GRB010126 optical observations
  76. GRB010126: Optical observations
  77. IPN/RXTE TRIANGULATION OF GRB010126
  78. GRB 010119, optical observations
  79. GRB010119: Optical observations
  80. Optical Observations of GRB 001018 at Keck
  81. GRB010119, Radio observations
  82. Optical observations of GRB 001018 with JCAM
  83. IPN TRIANGULATION OF GRB010109
  84. IPN TRIANGULATION OF GRB010109
  85. GRB010103, optical observations
  86. IPN triangulation of GRB010103
  87. GRB 001204: Ks observations
  88. H band observation of GRB 001212
  89. IPN triangulation of GRB001219
  90. GRB 001212 Optical Observation
  91. GRB 001212 Optical Observation
  92. GRB 001212 optical observation
  93. GRB 001212 possible OA in 2MASS
  94. GRB 001212 possible OA
  95. IPN triangulation of GRB001212
  96. GRB001204: Optical observations
  97. Confirmation of IPN position for GRB001204
  98. GRB001204, Radio observations
  99. IPN triangulation of GRB001204 (short/hard)
  100. GRB 001105, further optical observations

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