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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"

20483 results found.

  1. GRB 991014, Optical Observations
  2. GRB 991014 - BeppoSAX NFI observations
  3. GRB 991014, Optical Observations
  4. GRB 991014, radio observations
  5. GRB991014 BATSE Observations
  6. GRB 991014, Optical Observations
  7. GRB 991014, optical observations
  8. GRB 990915 optical observations
  9. GRB 990907 optical observations
  10. Optical Observations of GRB990907
  11. GRB990907 and 990908
  12. GRB 990712 Late Optical Decay and Host Galaxy
  13. GRB 990712, Optical Observation
  14. GRB990806: BATSE Observations
  15. GRB 990806 Optical observations
  16. Optical Observations of GRB990806
  17. GRB 990806, Optical Observations
  18. GRB 990806, optical observations
  19. GRB 990806, Optical Observations
  20. GRB990806 UBVRIJHK observations
  21. GRB 990712 Optical Observations
  22. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  23. GRB 990712
  24. Late-time HST/STIS Observations of GRB 990510
  25. GRB 990705, R-band observations
  26. Infrared and Optical Observations of GRB990705
  27. GRB 990705, radio observations
  28. GRB990704 radio and optical observations
  29. GRB 990704 X-ray Observations
  30. GRB 990704 Optical Observations
  31. GRB 990704, optical observations
  32. GRB990704
  33. GRB990704, optical observations
  34. Identification of a possible optical counterpart for GRB990704
  35. GRB990704
  36. Optical Observations of GRB990627
  37. GRB 990627, radio observations
  38. Late-time HST/STIS Observation of GRB 990123
  39. GRB 990506 - Optical Observations
  40. Optical Observations of GRB 990506
  41. GRB 990506 Radio Transient
  42. GRB990527 Optical Observations
  43. Late Afterglows of GRBs 990510, 990123
  44. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  45. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  46. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  47. radio observations of X-ray/GRB transient field
  48. radio detection of X-ray/GRB transient
  49. BeppoSAX: A new fast X-ray transient
  50. GRB 990510: optical observations
  51. GRB990510: photometric and spectroscopic observations with the VLT
  52. GRB 990510: optical observations
  53. GRB990510, VI observations
  54. GRB 990506 R band observations
  55. GRB990510: X-ray afterglow
  56. GRB 990510: Broad Band Break
  57. GRB 990510: BATSE Observations
  58. GRB 990510 Optical Observations
  59. GRB 990510, BVI photometry
  60. GRB 990510 optical observations
  61. GRB 990510: BeppoSAX/GRBM observations
  62. GRB990510 optical observations
  63. GRB990510
  64. GRB 990510 optical observations
  65. GRB 990510 optical observations
  66. GRB 990510 optical observations
  67. GRB 990506 Radio Observations
  68. GRB 990123, optical monitoring
  69. GRB 990506: BATSE Observations
  70. GRB 990506, optical observations
  71. GRB 990506, Optical Observations
  72. GRB 990506 optical observations
  73. GRB 990506 optical observations
  74. GRB 990506, optical observations
  75. GRB990506 observation plan
  76. GRB 990506: Limits on the possible optical transient
  77. GRB 990506, optical observations from +1 to +3 hours
  78. GRB 990506, optical observations
  79. GRB990506 Optical observations
  80. GRB981220 VLBA observations
  81. GRB980425 Optical observations of exponential decline at late time
  82. GRB 990316 Optical Observations
  83. GRB 990316, Radio observations
  84. GRB 990316, Optical observations
  85. GRB990316, Optical observations
  86. GRB 990316 optical observations
  87. GRB990316: simultaneous optical observation
  88. GRB990308 not a new SGR
  89. GRB990308 (Trig. 7457), optical observations
  90. GRB990308, Possible new SGR~0209+70
  91. GRB 981220, radio observations
  92. GRB 990217 Optical Observations
  93. GRB 990217, radio observations
  94. Optical Observations of GRB990217
  95. GRB990123 observations
  96. GRB990123, Optical Observation
  97. GRB 990123: Reduced HST Images
  98. For Immediate Posting to GCN - HST Data GRB 990123 Available
  99. GRB19990123 observations
  100. GRB981220, field photometry

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