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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"

41657 results found.

  1. GRB990705: Intriguing Positional Coincidences
  2. GRB990704
  3. GRB990704, optical observations
  4. Identification of a possible optical counterpart for GRB990704
  5. GRB990704
  6. Refined BeppoSAX-WFC position of GRB990704
  7. GRB990704: BeppoSAX detection
  8. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  9. Optical Observations of GRB990627
  10. GRB 990627, radio observations
  11. GRB990627: BeppoSAX-WFC final location
  12. BeppoSAX: GRB990625
  13. Late-time HST/STIS Observation of GRB 990123
  14. GRB 990506 - clarification to GCN 352
  15. GRB 990506 - Optical Observations
  16. Optical Observations of GRB 990506
  17. GRB 990506 Radio Transient
  18. GRB990527 Optical Observations
  19. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  20. IPN error box for GRB990527
  21. Late Afterglows of GRBs 990510, 990123
  22. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  23. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  24. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  25. GRB 990506 optical observation
  26. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  27. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  28. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  29. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  30. radio observations of X-ray/GRB transient field
  31. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  32. Optical report on X-ray/GRB transient
  33. radio detection of X-ray/GRB transient
  34. BeppoSAX: A new fast X-ray transient
  35. GRB 990510: optical observations
  36. GRB990510: photometric and spectroscopic observations with the VLT
  37. GRB 990510: optical observations
  38. GRB990510, VI observations
  39. GRB 990506 R band observations
  40. GRB990510: X-ray afterglow
  41. GRB 990510: optical observation
  42. VLT spectrum of GRB990510
  43. GRB 990510: Broad Band Break
  44. GRB 990510: BATSE Observations
  45. GRB 990510 Optical Observations
  46. GRB 990510, BVI photometry
  47. GRB 990510 optical observations
  48. GRB 990510: BeppoSAX/GRBM observations
  49. GRB990510 optical observations
  50. GRB990510
  51. GRB 990510 optical observations
  52. GRB 990510 optical observations
  53. Galactic extinction towards GRB 990510
  54. GRB 990510 optical observations
  55. IPN localization of GRB990510
  56. GRB 990506 Radio Observations
  57. GRB 990123, optical monitoring
  58. GRB 990506: BATSE Observations
  59. GRB 990506, optical observations
  60. GRB 990510: Final BeppoSAX-WFC Coordinates
  61. GRB 990506, Optical Observations
  62. GRB 990506 optical observations
  63. GRB 990506 optical observations
  64. GRB 990506, optical observations
  65. GRB990506 observation plan
  66. Refined IPN error box for GRB990506
  67. GRB 990506: Limits on the possible optical transient
  68. GRB 990506, optical observations from +1 to +3 hours
  69. GRB 990506, optical observations
  70. GRB990506 Optical observations
  71. GRB990506 observation plan
  72. New IPN/RXTE error box for GRB990506
  73. IPN localization for GRB990506
  74. GRB 970228: Redshift and properties of the host galaxy
  75. IPN localization of GRB990427
  76. GRB981220 VLBA observations
  77. GRB980425 Optical observations of exponential decline at late time
  78. GRB990321 REFINED IPN ANNULUS
  79. GRB990323 PRECISE IPN POSITION
  80. GRB990321 IPN TRIANGULATION
  81. GRB 990316 Optical Observations
  82. GRB 990316, Radio observations
  83. GRB 990316, Optical observations
  84. GRB990316, Optical observations
  85. GRB 990316 optical observations
  86. GRB990316: simultaneous optical observation
  87. GRB990316 - Optical null results
  88. ASM/IPN error box for GRB 990308 (BATSE #7457)
  89. GRB990308 not a new SGR
  90. GRB 990308a and GRB 990308b
  91. GRB990308 (Trig. 7457), optical observations
  92. GRB990308, Possible new SGR~0209+70
  93. GRB981220, IPN localization
  94. GRB 981220, radio observations
  95. GRB 990123, Field Photometry
  96. GRB 990217 Optical Observations
  97. GRB 990217, radio observations
  98. BATSE Resumes Normal Operations
  99. BATSE Flight Anomaly
  100. GRB990217: BeppoSAX/GRBM data

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