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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"

32489 results found.

  1. GRB 990712, Optical Observation
  2. GRB990806 BeppoSAX follow up
  3. GRB990806: BATSE Observations
  4. GRB 990806 Optical observations
  5. Optical Observations of GRB990806
  6. GRB 990806, Optical Observations
  7. GRB 990806, optical observations
  8. GRB 990806, Optical Observations
  9. GRB990806 UBVRIJHK observations
  10. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  11. VLT spectrum of GRB990712
  12. GRB 990712
  13. Late-time HST/STIS Observations of GRB 990510
  14. BeppoSAX NFI Observation of GRB990705
  15. BeppoSAX NFI Observation of GRB990705
  16. Updated Astrometry for the IR Counterpart of GRB990705
  17. GRB 990705, R-band observations
  18. Updated IPN localization of GRB990705
  19. IPN localization of GRB990704
  20. IPN localization of GRB990705
  21. Infrared and Optical Observations of GRB990705
  22. GRB 990705, radio observations
  23. GRB990704: SAX-NFI results summary
  24. GRB990704 radio and optical observations
  25. GRB 990704 X-ray Observations
  26. GRB 990704 Optical Observations
  27. GRB 990704, optical observations
  28. GRB990704
  29. GRB990704
  30. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  31. GRB990704, optical observations
  32. GRB990704: possible X-ray afterglow
  33. Identification of a possible optical counterpart for GRB990704
  34. GRB990704
  35. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  36. Optical Observations of GRB990627
  37. GRB 990627, radio observations
  38. GRB990627: BeppoSAX-WFC final location
  39. GRB 990506 - clarification to GCN 352
  40. GRB 990506 - Optical Observations
  41. Optical Observations of GRB 990506
  42. GRB 990506 Radio Transient
  43. GRB990527 Optical Observations
  44. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  45. Late Afterglows of GRBs 990510, 990123
  46. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  47. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  48. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  49. GRB 990506 optical observation
  50. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  51. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  52. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  53. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  54. radio observations of X-ray/GRB transient field
  55. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  56. Optical report on X-ray/GRB transient
  57. radio detection of X-ray/GRB transient
  58. BeppoSAX: A new fast X-ray transient
  59. GRB 990510: optical observations
  60. GRB990510, VI observations
  61. GRB 990506 R band observations
  62. GRB990510: X-ray afterglow
  63. VLT spectrum of GRB990510
  64. GRB 990510: Broad Band Break
  65. GRB 990510: BATSE Observations
  66. GRB990510: optical observation
  67. GRB 990510 Optical Observations
  68. GRB 990510, BVI photometry
  69. GRB 990510 optical observations
  70. GRB990510 optical observations
  71. GRB990510
  72. GRB 990510 optical observations
  73. GRB 990510 optical observations
  74. Galactic extinction towards GRB 990510
  75. IPN localization of GRB990510
  76. GRB 990506 Radio Observations
  77. GRB 990506: BATSE Observations
  78. GRB 990506, optical observations
  79. GRB 990506, Optical Observations
  80. GRB 990506 optical observations
  81. GRB 990506 optical observations
  82. GRB 990506, optical observations
  83. GRB990506 observation plan
  84. GRB 990506: Limits on the possible optical transient
  85. GRB 990506, armchair astronomy
  86. GRB 990506, optical observations from +1 to +3 hours
  87. GRB 990506, optical observations
  88. GRB990506 observation plan
  89. New IPN/RXTE error box for GRB990506
  90. IPN localization for GRB990506
  91. GRB 970228: Redshift and properties of the host galaxy
  92. GRB981220 VLBA observations
  93. GRB990321 REFINED IPN ANNULUS
  94. GRB990323 PRECISE IPN POSITION
  95. GRB 990316 Optical Observations
  96. GRB 990316, Radio observations
  97. GRB 990316, Optical observations
  98. GRB990316, Optical observations
  99. GRB 990316 optical observations
  100. GRB990316: simultaneous optical observation

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