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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"

32491 results found.

  1. IPN localization of GRB990907
  2. GRB 990712 Late Optical Decay and Host Galaxy
  3. GRB 990712, Optical Observation
  4. GRB990806 BeppoSAX follow up
  5. GRB990806: BATSE Observations
  6. GRB 990806 Optical observations
  7. Optical Observations of GRB990806
  8. GRB 990806, Optical Observations
  9. GRB 990806, optical observations
  10. GRB 990806, Optical Observations
  11. GRB990806 UBVRIJHK observations
  12. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  13. VLT spectrum of GRB990712
  14. GRB 990712
  15. Late-time HST/STIS Observations of GRB 990510
  16. BeppoSAX NFI Observation of GRB990705
  17. BeppoSAX NFI Observation of GRB990705
  18. Updated Astrometry for the IR Counterpart of GRB990705
  19. GRB 990705, R-band observations
  20. Updated IPN localization of GRB990705
  21. IPN localization of GRB990704
  22. IPN localization of GRB990705
  23. Infrared and Optical Observations of GRB990705
  24. GRB 990705, radio observations
  25. GRB990704: SAX-NFI results summary
  26. GRB990704 radio and optical observations
  27. GRB 990704 X-ray Observations
  28. GRB 990704 Optical Observations
  29. GRB 990704, optical observations
  30. GRB990704
  31. GRB990704
  32. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  33. GRB990704, optical observations
  34. GRB990704: possible X-ray afterglow
  35. Identification of a possible optical counterpart for GRB990704
  36. GRB990704
  37. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  38. Optical Observations of GRB990627
  39. GRB 990627, radio observations
  40. GRB990627: BeppoSAX-WFC final location
  41. GRB 990506 - clarification to GCN 352
  42. GRB 990506 - Optical Observations
  43. Optical Observations of GRB 990506
  44. GRB 990506 Radio Transient
  45. GRB990527 Optical Observations
  46. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  47. Late Afterglows of GRBs 990510, 990123
  48. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  49. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  50. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  51. GRB 990506 optical observation
  52. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  53. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  54. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  55. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  56. radio observations of X-ray/GRB transient field
  57. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  58. Optical report on X-ray/GRB transient
  59. radio detection of X-ray/GRB transient
  60. BeppoSAX: A new fast X-ray transient
  61. GRB 990510: optical observations
  62. GRB990510, VI observations
  63. GRB 990506 R band observations
  64. GRB990510: X-ray afterglow
  65. VLT spectrum of GRB990510
  66. GRB 990510: Broad Band Break
  67. GRB 990510: BATSE Observations
  68. GRB990510: optical observation
  69. GRB 990510 Optical Observations
  70. GRB 990510, BVI photometry
  71. GRB 990510 optical observations
  72. GRB990510 optical observations
  73. GRB990510
  74. GRB 990510 optical observations
  75. GRB 990510 optical observations
  76. Galactic extinction towards GRB 990510
  77. IPN localization of GRB990510
  78. GRB 990506 Radio Observations
  79. GRB 990506: BATSE Observations
  80. GRB 990506, optical observations
  81. GRB 990506, Optical Observations
  82. GRB 990506 optical observations
  83. GRB 990506 optical observations
  84. GRB 990506, optical observations
  85. GRB990506 observation plan
  86. GRB 990506: Limits on the possible optical transient
  87. GRB 990506, armchair astronomy
  88. GRB 990506, optical observations from +1 to +3 hours
  89. GRB 990506, optical observations
  90. GRB990506 observation plan
  91. New IPN/RXTE error box for GRB990506
  92. IPN localization for GRB990506
  93. GRB 970228: Redshift and properties of the host galaxy
  94. GRB981220 VLBA observations
  95. GRB990321 REFINED IPN ANNULUS
  96. GRB990323 PRECISE IPN POSITION
  97. GRB 990316 Optical Observations
  98. GRB 990316, Radio observations
  99. GRB 990316, Optical observations
  100. GRB990316, Optical observations

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