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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. REVISED LOCATION OF GRB010326A
  2. GRB 980326: Late-time HST/STIS observations
  3. GRB010324, field photometry
  4. GRB010326B, field photometry
  5. GRB010326, field photometry
  6. GRB010220, field photometry
  7. Further Optical Observations of GRB 010324
  8. GRB010222, CXO X-ray observations
  9. GRB 010326A: Further optical observations
  10. GRB010324: BeppoSAX/GRBM data
  11. GRB 010326B: Optical observations
  12. GRB010324, optical observations
  13. GRB010326B: Localization by HETE (2nd GRB for this date)
  14. GRB 010326: Optical observations
  15. GRB 010326 optical observations
  16. GRB010326: Refined Localization by HETE
  17. GRB010326: Localization by HETE
  18. Duration, ECT, peak flux and fluence of GRB010324
  19. Optical Observations of GRB 010324
  20. IPN TRIANGULATION OF GRB010324
  21. GRB990705, VLT-FORS1 observations of the host galaxy
  22. GRB010222, late-time optical observation
  23. Support extension to the BeppoSAX mission
  24. GRB 010222 - HEGRA GeV/TeV Observations
  25. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  26. GRB010222: Chandra X-ray Observatory Observation
  27. GRB010222: Sub-millimeter vanishing act
  28. GRB010222 - Optical observation
  29. GRB 010222, Optical Observations
  30. GRB010220 optical obsercations
  31. GRB010222 - Optical observation
  32. GRB 010222: High-Resolution Keck Spectroscopy
  33. GRB010222: Optical observation and decay
  34. GRB 010214, I-band data
  35. Sub-millimeter Excess/GRB 010222
  36. GRB 010222
  37. GRB 010222 HST/Chandra TOO
  38. GRB 010222
  39. GRB010222 further R-band photometry
  40. GRB010222: R-band data
  41. GRB010222 Optical observations
  42. GRB 010222: Keck Spectroscopy
  43. GRB010214, field photometry
  44. GRB010222, field photometry
  45. GRB010222 further R-band photometry
  46. GRB010222, possible increase of optical decay slope
  47. GRB 010222 Kyoto optical observation
  48. GRB010222: fading behavior
  49. GRB 010222 BV optical observations
  50. GRB010220, Optical Observations
  51. GRB010222 R-BAND OBSERVATION
  52. GRB 010220: Near-IR Observations
  53. GRB010214 follow-up from Hanle
  54. GRB 010222: Near-IR Observations
  55. GRB 010222: Optical Observations
  56. GRB 010222, Decay Slope Confirmed
  57. GRB010222: Another absorption line system
  58. GRB010222: Optical decay slope
  59. GRB 010214, Optical Observations
  60. GRB010222: Sub-millimeter detection
  61. GRB010222: R-band fading behavior
  62. GRB010222: Optical Observations
  63. GRB010222, radio observations
  64. GRB010222, optical observations
  65. GRB010222: BeppoSAX/NFI Observations
  66. Redshift of the Optical Transient of GRB010222
  67. GRB010214B,Gamma Ray Observations
  68. GRB010222: possible optical counterpart
  69. GRB010222
  70. GRB010222
  71. GRB010222: BeppoSAX refined position
  72. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  73. GRB010220, Radio and Optical Observations
  74. GRB 010220, simultaneous optical observations
  75. GRB010220: BeppoSAX WFC and GRBM preliminary data
  76. GRB010214, candidate optical afterglow
  77. GRB010214, optical observations
  78. BeppoSAX GRB010220: refined position
  79. BeppoSAX ALERT: GRB010220
  80. GRB010214: BeppoSAX WFC and GRBM preliminary data
  81. GRB 010214: X-Ray afterglow
  82. GRB 010214, Optical Observations
  83. GRB 010214 optical observation
  84. GRB010213, Radio Observations
  85. GRB010213 Optical Observation
  86. GRB010213, Radio Observations
  87. J-Band Observation of GRB 010214.
  88. GRB010214, Radio Observations
  89. GRB010214, optical observations
  90. GRB010213, optical observations
  91. GRB010213, Near-IR observations
  92. Possible InfraRed Transient of GRB 010214.
  93. GRB010214 Optical Observation
  94. GRB010214: BeppoSAX/NFI Observations
  95. GRB010213 (HETE) TAROT observations
  96. GRB 010214, optical observations
  97. GRB010213 detected by HETE
  98. GRB010214 refined WFC position
  99. BeppoSAX ALERT: GRB010214
  100. IPN Status Report

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