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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"

25577 results found.

  1. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  2. GRB ALERT: GRB991105
  3. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  4. GRB 991014, radio observations
  5. GRB991014 BATSE Observations
  6. GRB 991014, optical observations
  7. IPN/NFI error box for GRB991014
  8. BeppoSAX ALERT: GRB991014
  9. GRB 990915 optical observations
  10. GRB 990907 optical observations
  11. GRB990907 and 990908
  12. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  13. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  14. GRB 990712 Late Optical Decay and Host Galaxy
  15. GRB 990712, Optical Observation
  16. GRB990806 BeppoSAX follow up
  17. GRB990806: BATSE Observations
  18. Optical Observations of GRB990806
  19. GRB 990806, Optical Observations
  20. BeppoSAX ALERT GRB990806: Summer GRB
  21. GRB 990712 Optical Observations
  22. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  23. Late-time HST/STIS Observations of GRB 990510
  24. Refined BeppoSAX-WFC position of GRB990712
  25. BeppoSAX NFI Observation of GRB990705
  26. BeppoSAX NFI Observation of GRB990705
  27. GRB 990705, radio observations
  28. GRB 990704, optical observations
  29. GRB990704
  30. GRB990704, optical observations
  31. Refined BeppoSAX-WFC position of GRB990704
  32. GRB990704: BeppoSAX detection
  33. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  34. Optical Observations of GRB990627
  35. GRB 990627, radio observations
  36. GRB990627: BeppoSAX-WFC final location
  37. BeppoSAX: GRB990625
  38. Late-time HST/STIS Observation of GRB 990123
  39. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  40. Late Afterglows of GRBs 990510, 990123
  41. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  42. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  43. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  44. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  45. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  46. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  47. radio observations of X-ray/GRB transient field
  48. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  49. Optical report on X-ray/GRB transient
  50. radio detection of X-ray/GRB transient
  51. BeppoSAX: A new fast X-ray transient
  52. GRB990510: photometric and spectroscopic observations with the VLT
  53. GRB 990510: optical observations
  54. GRB 990506 R band observations
  55. VLT spectrum of GRB990510
  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. GRB 990510 optical observations
  64. GRB 990510 optical observations
  65. GRB 990506: BATSE Observations
  66. GRB 990506, optical observations
  67. GRB 990510: Final BeppoSAX-WFC Coordinates
  68. GRB 990506, Optical Observations
  69. GRB 990506 optical observations
  70. GRB 990506 optical observations
  71. GRB990506 observation plan
  72. Refined IPN error box for GRB990506
  73. GRB 990506: Limits on the possible optical transient
  74. GRB 990506, optical observations from +1 to +3 hours
  75. IPN localization for GRB990506
  76. GRB 970228: Redshift and properties of the host galaxy
  77. IPN localization of GRB990427
  78. GRB981220 VLBA observations
  79. GRB980425 Optical observations of exponential decline at late time
  80. GRB990321 IPN TRIANGULATION
  81. GRB 990316, Radio observations
  82. GRB 990316, Optical observations
  83. GRB 990316 optical observations
  84. GRB990316: simultaneous optical observation
  85. ASM/IPN error box for GRB 990308 (BATSE #7457)
  86. GRB990308 (Trig. 7457), optical observations
  87. GRB990308, Possible new SGR~0209+70
  88. GRB981220, IPN localization
  89. GRB 981220, radio observations
  90. BATSE Resumes Normal Operations
  91. BATSE Flight Anomaly
  92. GRB990217: BeppoSAX/GRBM data
  93. Optical Observations of GRB990217
  94. GRB990123: Caltech STIS Photometry and Images
  95. GRB990123 observations
  96. GRB990123, Optical Observation
  97. GRB 990123: Discovery of the Probable Host Galaxy
  98. GRB 990123: Reduced HST Images
  99. For Immediate Posting to GCN - HST Data GRB 990123 Available
  100. GRB19990123 observations

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