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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"

32501 results found.

  1. IPN/NFI error box for GRB991014
  2. IPN localization of GRB991014 - CORRECTION
  3. IPN localization of GRB991014
  4. GRB 990915 optical observations
  5. GRB 990907 optical observations
  6. Optical Observations of GRB990907
  7. IPN error box for GRB990915 (=BATSE 7766)
  8. IPN localization of BATSE #7766 (GRB990915)
  9. GRB990907: BeppoSAX follow up and X-ray afterglow
  10. GRB990907 and 990908
  11. IPN localization of GRB990907
  12. GRB 990712 Late Optical Decay and Host Galaxy
  13. GRB 990712, Optical Observation
  14. GRB990806 BeppoSAX follow up
  15. GRB990806: BATSE Observations
  16. GRB 990806 Optical observations
  17. Optical Observations of GRB990806
  18. GRB 990806, Optical Observations
  19. GRB 990806, optical observations
  20. GRB 990806, Optical Observations
  21. GRB990806 UBVRIJHK observations
  22. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  23. VLT spectrum of GRB990712
  24. GRB 990712
  25. Late-time HST/STIS Observations of GRB 990510
  26. BeppoSAX NFI Observation of GRB990705
  27. BeppoSAX NFI Observation of GRB990705
  28. Updated Astrometry for the IR Counterpart of GRB990705
  29. GRB 990705, R-band observations
  30. Updated IPN localization of GRB990705
  31. IPN localization of GRB990704
  32. IPN localization of GRB990705
  33. Infrared and Optical Observations of GRB990705
  34. GRB 990705, radio observations
  35. GRB990704: SAX-NFI results summary
  36. GRB990704 radio and optical observations
  37. GRB 990704 X-ray Observations
  38. GRB 990704 Optical Observations
  39. GRB 990704, optical observations
  40. GRB990704
  41. GRB990704
  42. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  43. GRB990704, optical observations
  44. GRB990704: possible X-ray afterglow
  45. Identification of a possible optical counterpart for GRB990704
  46. GRB990704
  47. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  48. Optical Observations of GRB990627
  49. GRB 990627, radio observations
  50. GRB990627: BeppoSAX-WFC final location
  51. GRB 990506 - clarification to GCN 352
  52. GRB 990506 - Optical Observations
  53. Optical Observations of GRB 990506
  54. GRB 990506 Radio Transient
  55. GRB990527 Optical Observations
  56. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  57. Late Afterglows of GRBs 990510, 990123
  58. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  59. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  60. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  61. GRB 990506 optical observation
  62. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  63. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  64. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  65. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  66. radio observations of X-ray/GRB transient field
  67. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  68. Optical report on X-ray/GRB transient
  69. radio detection of X-ray/GRB transient
  70. BeppoSAX: A new fast X-ray transient
  71. GRB 990510: optical observations
  72. GRB990510, VI observations
  73. GRB 990506 R band observations
  74. GRB990510: X-ray afterglow
  75. VLT spectrum of GRB990510
  76. GRB 990510: Broad Band Break
  77. GRB 990510: BATSE Observations
  78. GRB990510: optical observation
  79. GRB 990510 Optical Observations
  80. GRB 990510, BVI photometry
  81. GRB 990510 optical observations
  82. GRB990510 optical observations
  83. GRB990510
  84. GRB 990510 optical observations
  85. GRB 990510 optical observations
  86. Galactic extinction towards GRB 990510
  87. IPN localization of GRB990510
  88. GRB 990506 Radio Observations
  89. GRB 990506: BATSE Observations
  90. GRB 990506, optical observations
  91. GRB 990506, Optical Observations
  92. GRB 990506 optical observations
  93. GRB 990506 optical observations
  94. GRB 990506, optical observations
  95. GRB990506 observation plan
  96. GRB 990506: Limits on the possible optical transient
  97. GRB 990506, armchair astronomy
  98. GRB 990506, optical observations from +1 to +3 hours
  99. GRB 990506, optical observations
  100. GRB990506 observation plan

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