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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"

31734 results found.

  1. GRB010222, CXO X-ray observations
  2. GRB010324: BeppoSAX/GRBM data
  3. GRB010324, optical observations
  4. Duration, ECT, peak flux and fluence of GRB010324
  5. Optical Observations of GRB 010324
  6. IPN TRIANGULATION OF GRB010324
  7. GRB990705, VLT-FORS1 observations of the host galaxy
  8. GRB010222, late-time optical observation
  9. GRB 010222 - HEGRA GeV/TeV Observations
  10. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  11. GRB010222: Chandra X-ray Observatory Observation
  12. GRB010222: Sub-millimeter vanishing act
  13. GRB010222 - Optical observation
  14. GRB 010222, Optical Observations
  15. GRB010220 optical obsercations
  16. GRB010222 - Optical observation
  17. GRB 010222: High-Resolution Keck Spectroscopy
  18. GRB010222: Optical observation and decay
  19. GRB 010214, I-band data
  20. Sub-millimeter Excess/GRB 010222
  21. GRB 010222
  22. GRB 010222 HST/Chandra TOO
  23. GRB010222 further R-band photometry
  24. GRB010222: R-band data
  25. GRB010222 Optical observations
  26. GRB 010222: Keck Spectroscopy
  27. GRB010222 further R-band photometry
  28. GRB010222, possible increase of optical decay slope
  29. GRB010222: fading behavior
  30. GRB 010222 BV optical observations
  31. GRB010222 R-BAND OBSERVATION
  32. GRB 010220: Near-IR Observations
  33. GRB010214 follow-up from Hanle
  34. GRB 010222: Near-IR Observations
  35. GRB 010222: Optical Observations
  36. GRB 010222, Decay Slope Confirmed
  37. GRB010222: Another absorption line system
  38. GRB010222: Optical decay slope
  39. GRB 010214, Optical Observations
  40. GRB010222: Sub-millimeter detection
  41. GRB010222: R-band fading behavior
  42. GRB010222: Optical Observations
  43. GRB010222, radio observations
  44. GRB010222, optical observations
  45. GRB010222: BeppoSAX/NFI Observations
  46. Redshift of the Optical Transient of GRB010222
  47. GRB010222: possible optical counterpart
  48. GRB010222
  49. GRB010222: BeppoSAX refined position
  50. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  51. GRB010220, Radio and Optical Observations
  52. GRB 010220, simultaneous optical observations
  53. GRB010220: BeppoSAX WFC and GRBM preliminary data
  54. GRB010214, candidate optical afterglow
  55. GRB010214, optical observations
  56. GRB010214: BeppoSAX WFC and GRBM preliminary data
  57. GRB 010214: X-Ray afterglow
  58. GRB 010214, Optical Observations
  59. GRB 010214 optical observation
  60. GRB010213, Radio Observations
  61. GRB010213 Optical Observation
  62. GRB010213, Radio Observations
  63. J-Band Observation of GRB 010214.
  64. GRB010214, Radio Observations
  65. GRB010214, optical observations
  66. GRB010213, optical observations
  67. Possible InfraRed Transient of GRB 010214.
  68. GRB010214 Optical Observation
  69. GRB010213 (HETE) TAROT observations
  70. GRB 010214, optical observations
  71. IPN Status Report
  72. HETE Status
  73. GRB010126 opt. obs.
  74. IPN/RXTE TRIANGULATION OF GRB010126
  75. GRB010126: CONCAM crude optical limits during GRB
  76. GRB010126, TNG R-band observations
  77. GRB010126 Optical Observations
  78. GRB010126 optical observations
  79. GRB010126: Optical observations
  80. IPN/RXTE TRIANGULATION OF GRB010126
  81. GRB 010119, optical observations
  82. GRB010119: Optical observations
  83. Optical Observations of GRB 001018 at Keck
  84. GRB010119, Radio observations
  85. Optical observations of GRB 001018 with JCAM
  86. IPN TRIANGULATION OF GRB010109
  87. GRB 001204: Ks observations
  88. H band observation of GRB 001212
  89. GRB 001212 Optical Observation
  90. GRB 001212 Optical Observation
  91. GRB 001212 optical observation
  92. GRB 001212 possible OA in 2MASS
  93. GRB 001212 possible OA
  94. GRB001204: Optical observations
  95. Confirmation of IPN position for GRB001204
  96. GRB001204, Radio observations
  97. GRB 001105, further optical observations
  98. GRB001120: Gunn-i observations
  99. GRB001109, optical observations
  100. WSRT 4.8 GHz observations of GRB001109

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