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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"

40743 results found.

  1. GRB990704
  2. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  3. GRB990704, optical observations
  4. GRB990704: possible X-ray afterglow
  5. Identification of a possible optical counterpart for GRB990704
  6. GRB990704
  7. Refined BeppoSAX-WFC position of GRB990704
  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. Late-time HST/STIS Observation of GRB 990123
  13. GRB 990506 - clarification to GCN 352
  14. GRB 990506 - Optical Observations
  15. Optical Observations of GRB 990506
  16. GRB 990506 Radio Transient
  17. GRB990527 Optical Observations
  18. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  19. Late Afterglows of GRBs 990510, 990123
  20. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  21. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  22. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  23. GRB 990506 optical observation
  24. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  25. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  26. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  27. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  28. radio observations of X-ray/GRB transient field
  29. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  30. Optical report on X-ray/GRB transient
  31. radio detection of X-ray/GRB transient
  32. BeppoSAX: A new fast X-ray transient
  33. GRB 990510: optical linear polarization
  34. GRB 990510: optical observations
  35. GRB990510, VI observations
  36. GRB 990506 R band observations
  37. GRB990510: X-ray afterglow
  38. GRB 990510: optical observation
  39. VLT spectrum of GRB990510
  40. GRB 990510: Broad Band Break
  41. GRB 990510: BATSE Observations
  42. GRB990510: optical observation
  43. GRB 990510 Optical Observations
  44. GRB 990510, BVI photometry
  45. GRB 990510 optical observations
  46. GRB 990510: BeppoSAX/GRBM observations
  47. GRB990510 optical observations
  48. GRB990510
  49. GRB 990510 optical observations
  50. GRB 990510 optical observations
  51. Galactic extinction towards GRB 990510
  52. GRB990510: NFI X-ray source
  53. GRB 990510 optical observations
  54. IPN localization of GRB990510
  55. GRB 990506 Radio Observations
  56. GRB 990123, optical monitoring
  57. GRB 990506: BATSE Observations
  58. GRB 990506, optical observations
  59. GRB 990506, Optical Observations
  60. GRB 990506 optical observations
  61. GRB 990506 optical observations
  62. GRB 990506, optical observations
  63. GRB990506 observation plan
  64. Refined IPN error box for GRB990506
  65. GRB 990506: Limits on the possible optical transient
  66. GRB 990506, armchair astronomy
  67. GRB 990506, optical observations from +1 to +3 hours
  68. GRB 990506, optical observations
  69. GRB990506 Optical observations
  70. GRB990506 observation plan
  71. New IPN/RXTE error box for GRB990506
  72. IPN localization for GRB990506
  73. GRB 970228: Redshift and properties of the host galaxy
  74. GRB981220 VLBA observations
  75. GRB980425 Optical observations of exponential decline at late time
  76. GRB990321 REFINED IPN ANNULUS
  77. GRB990323 PRECISE IPN POSITION
  78. GRB990321 IPN TRIANGULATION
  79. GRB 990316 Optical Observations
  80. GRB 990316, Radio observations
  81. GRB 990316, Optical observations
  82. GRB990316, Optical observations
  83. GRB 990316 optical observations
  84. GRB990316: simultaneous optical observation
  85. ASM/IPN error box for GRB 990308 (BATSE #7457)
  86. GRB990308 not a new SGR
  87. GRB 990308a and GRB 990308b
  88. GRB990308 (Trig. 7457), optical observations
  89. GRB990308, Possible new SGR~0209+70
  90. GRB981220, IPN localization
  91. GRB 981220, radio observations
  92. GRB 990123, Field Photometry
  93. GRB 990217 Optical Observations
  94. GRB 990217, radio observations
  95. BATSE Resumes Normal Operations
  96. BATSE Flight Anomaly
  97. GRB990217: BeppoSAX/GRBM data
  98. Optical Observations of GRB990217
  99. GRB990123: Caltech STIS Photometry and Images
  100. GRB990123 observations

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