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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"

32503 results found.

  1. GRB 991014, optical observations
  2. Super-LOTIS optical observation of GRB991014
  3. IPN/NFI error box for GRB991014
  4. IPN localization of GRB991014 - CORRECTION
  5. IPN localization of GRB991014
  6. GRB 990915 optical observations
  7. GRB 990907 optical observations
  8. Optical Observations of GRB990907
  9. IPN error box for GRB990915 (=BATSE 7766)
  10. IPN localization of BATSE #7766 (GRB990915)
  11. GRB990907: BeppoSAX follow up and X-ray afterglow
  12. GRB990907 and 990908
  13. IPN localization of GRB990907
  14. GRB 990712 Late Optical Decay and Host Galaxy
  15. GRB 990712, Optical Observation
  16. GRB990806 BeppoSAX follow up
  17. GRB990806: BATSE Observations
  18. GRB 990806 Optical observations
  19. Optical Observations of GRB990806
  20. GRB 990806, Optical Observations
  21. GRB 990806, optical observations
  22. GRB 990806, Optical Observations
  23. GRB990806 UBVRIJHK observations
  24. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  25. VLT spectrum of GRB990712
  26. GRB 990712
  27. Late-time HST/STIS Observations of GRB 990510
  28. BeppoSAX NFI Observation of GRB990705
  29. BeppoSAX NFI Observation of GRB990705
  30. Updated Astrometry for the IR Counterpart of GRB990705
  31. GRB 990705, R-band observations
  32. Updated IPN localization of GRB990705
  33. IPN localization of GRB990704
  34. IPN localization of GRB990705
  35. Infrared and Optical Observations of GRB990705
  36. GRB 990705, radio observations
  37. GRB990704: SAX-NFI results summary
  38. GRB990704 radio and optical observations
  39. GRB 990704 X-ray Observations
  40. GRB 990704 Optical Observations
  41. GRB 990704, optical observations
  42. GRB990704
  43. GRB990704
  44. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  45. GRB990704, optical observations
  46. GRB990704: possible X-ray afterglow
  47. Identification of a possible optical counterpart for GRB990704
  48. GRB990704
  49. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  50. Optical Observations of GRB990627
  51. GRB 990627, radio observations
  52. GRB990627: BeppoSAX-WFC final location
  53. GRB 990506 - clarification to GCN 352
  54. GRB 990506 - Optical Observations
  55. Optical Observations of GRB 990506
  56. GRB 990506 Radio Transient
  57. GRB990527 Optical Observations
  58. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  59. Late Afterglows of GRBs 990510, 990123
  60. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  61. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  62. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  63. GRB 990506 optical observation
  64. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  65. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  66. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  67. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  68. radio observations of X-ray/GRB transient field
  69. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  70. Optical report on X-ray/GRB transient
  71. radio detection of X-ray/GRB transient
  72. BeppoSAX: A new fast X-ray transient
  73. GRB 990510: optical observations
  74. GRB990510, VI observations
  75. GRB 990506 R band observations
  76. GRB990510: X-ray afterglow
  77. VLT spectrum of GRB990510
  78. GRB 990510: Broad Band Break
  79. GRB 990510: BATSE Observations
  80. GRB990510: optical observation
  81. GRB 990510 Optical Observations
  82. GRB 990510, BVI photometry
  83. GRB 990510 optical observations
  84. GRB990510 optical observations
  85. GRB990510
  86. GRB 990510 optical observations
  87. GRB 990510 optical observations
  88. Galactic extinction towards GRB 990510
  89. IPN localization of GRB990510
  90. GRB 990506 Radio Observations
  91. GRB 990506: BATSE Observations
  92. GRB 990506, optical observations
  93. GRB 990506, Optical Observations
  94. GRB 990506 optical observations
  95. GRB 990506 optical observations
  96. GRB 990506, optical observations
  97. GRB990506 observation plan
  98. GRB 990506: Limits on the possible optical transient
  99. GRB 990506, armchair astronomy
  100. GRB 990506, optical observations from +1 to +3 hours

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