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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"

38347 results found.

  1. BeppoSAX GRB ALERT: GRB010412
  2. GRB010324, revised field photometry
  3. REVISED LOCATION OF GRB010326A
  4. GRB 980326: Late-time HST/STIS observations
  5. GRB010324, field photometry
  6. GRB010326B, field photometry
  7. GRB010326, field photometry
  8. GRB010220, field photometry
  9. Further Optical Observations of GRB 010324
  10. GRB010222, CXO X-ray observations
  11. GRB 010326A: Further optical observations
  12. GRB010324: BeppoSAX/GRBM data
  13. GRB 010326B: Optical observations
  14. GRB010324, optical observations
  15. GRB010326B: Localization by HETE (2nd GRB for this date)
  16. GRB 010326: Optical observations
  17. GRB 010326 optical observations
  18. GRB010326: Refined Localization by HETE
  19. GRB010326: Localization by HETE
  20. Duration, ECT, peak flux and fluence of GRB010324
  21. Optical Observations of GRB 010324
  22. IPN TRIANGULATION OF GRB010324
  23. GRB990705, VLT-FORS1 observations of the host galaxy
  24. GRB010222, late-time optical observation
  25. Support extension to the BeppoSAX mission
  26. GRB 010222 - HEGRA GeV/TeV Observations
  27. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  28. GRB010222: Chandra X-ray Observatory Observation
  29. GRB010222: Sub-millimeter vanishing act
  30. GRB010222 - Optical observation
  31. GRB010220 optical obsercations
  32. GRB010222 - Optical observation
  33. GRB 010222: High-Resolution Keck Spectroscopy
  34. GRB010222: Optical observation and decay
  35. GRB 010214, I-band data
  36. Sub-millimeter Excess/GRB 010222
  37. GRB 010222
  38. GRB 010222 HST/Chandra TOO
  39. GRB010222 further R-band photometry
  40. GRB010222 Optical observations
  41. GRB 010222: Keck Spectroscopy
  42. GRB010214, field photometry
  43. GRB010222, field photometry
  44. GRB010222 further R-band photometry
  45. GRB010222, possible increase of optical decay slope
  46. GRB 010222 Kyoto optical observation
  47. GRB 010222 BV optical observations
  48. GRB010220, Optical Observations
  49. GRB010222 R-BAND OBSERVATION
  50. GRB 010220: Near-IR Observations
  51. GRB010214 follow-up from Hanle
  52. GRB 010222: Near-IR Observations
  53. GRB 010222: Optical Observations
  54. GRB 010222, Decay Slope Confirmed
  55. GRB010222: Another absorption line system
  56. GRB010222: Optical decay slope
  57. GRB 010214, Optical Observations
  58. GRB010222: Sub-millimeter detection
  59. GRB010222: Optical Observations
  60. GRB010222, radio observations
  61. GRB010222, optical observations
  62. GRB010222: BeppoSAX/NFI Observations
  63. Redshift of the Optical Transient of GRB010222
  64. GRB010214B,Gamma Ray Observations
  65. GRB010222: possible optical counterpart
  66. GRB010222
  67. GRB010222: BeppoSAX refined position
  68. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  69. GRB010220, Radio and Optical Observations
  70. GRB 010220, simultaneous optical observations
  71. GRB010220: BeppoSAX WFC and GRBM preliminary data
  72. GRB010214, candidate optical afterglow
  73. GRB010214, optical observations
  74. BeppoSAX ALERT: GRB010220
  75. GRB010214: BeppoSAX WFC and GRBM preliminary data
  76. GRB 010214: X-Ray afterglow
  77. GRB 010214 optical observation
  78. GRB010213, Radio Observations
  79. GRB010213 Optical Observation
  80. GRB010213, Radio Observations
  81. J-Band Observation of GRB 010214.
  82. GRB010214, Radio Observations
  83. GRB010214, optical observations
  84. GRB010213, optical observations
  85. GRB010213, Near-IR observations
  86. Possible InfraRed Transient of GRB 010214.
  87. GRB010214 Optical Observation
  88. GRB010214: BeppoSAX/NFI Observations
  89. GRB010213 (HETE) TAROT observations
  90. GRB 010214, optical observations
  91. GRB010213 detected by HETE
  92. GRB010214 refined WFC position
  93. BeppoSAX ALERT: GRB010214
  94. IPN Status Report
  95. GRB010126 opt. obs.
  96. IPN/RXTE TRIANGULATION OF GRB010126
  97. GRB010126: CONCAM crude optical limits during GRB
  98. GRB010126, TNG R-band observations
  99. GRB010126 Optical Observations
  100. GRB010126 optical observations

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