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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"

32488 results found.

  1. GRB990806 BeppoSAX follow up
  2. GRB990806: BATSE Observations
  3. GRB 990806 Optical observations
  4. Optical Observations of GRB990806
  5. GRB 990806, Optical Observations
  6. GRB 990806, optical observations
  7. GRB 990806, Optical Observations
  8. GRB990806 UBVRIJHK observations
  9. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  10. VLT spectrum of GRB990712
  11. GRB 990712
  12. Late-time HST/STIS Observations of GRB 990510
  13. BeppoSAX NFI Observation of GRB990705
  14. BeppoSAX NFI Observation of GRB990705
  15. Updated Astrometry for the IR Counterpart of GRB990705
  16. GRB 990705, R-band observations
  17. Updated IPN localization of GRB990705
  18. IPN localization of GRB990704
  19. IPN localization of GRB990705
  20. Infrared and Optical Observations of GRB990705
  21. GRB 990705, radio observations
  22. GRB990704: SAX-NFI results summary
  23. GRB990704 radio and optical observations
  24. GRB 990704 X-ray Observations
  25. GRB 990704 Optical Observations
  26. GRB 990704, optical observations
  27. GRB990704
  28. GRB990704
  29. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  30. GRB990704, optical observations
  31. GRB990704: possible X-ray afterglow
  32. Identification of a possible optical counterpart for GRB990704
  33. GRB990704
  34. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  35. Optical Observations of GRB990627
  36. GRB 990627, radio observations
  37. GRB990627: BeppoSAX-WFC final location
  38. GRB 990506 - clarification to GCN 352
  39. GRB 990506 - Optical Observations
  40. Optical Observations of GRB 990506
  41. GRB 990506 Radio Transient
  42. GRB990527 Optical Observations
  43. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  44. Late Afterglows of GRBs 990510, 990123
  45. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  46. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  47. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  48. GRB 990506 optical observation
  49. X-ray/GRB 1SAX J0835.9+5118, 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. radio observations of X-ray/GRB transient field
  54. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  55. Optical report on X-ray/GRB transient
  56. radio detection of X-ray/GRB transient
  57. BeppoSAX: A new fast X-ray transient
  58. GRB 990510: optical observations
  59. GRB990510, VI observations
  60. GRB 990506 R band observations
  61. GRB990510: X-ray afterglow
  62. VLT spectrum of GRB990510
  63. GRB 990510: Broad Band Break
  64. GRB 990510: BATSE Observations
  65. GRB990510: optical observation
  66. GRB 990510 Optical Observations
  67. GRB 990510, BVI photometry
  68. GRB 990510 optical observations
  69. GRB990510 optical observations
  70. GRB990510
  71. GRB 990510 optical observations
  72. GRB 990510 optical observations
  73. Galactic extinction towards GRB 990510
  74. IPN localization of GRB990510
  75. GRB 990506 Radio Observations
  76. GRB 990506: BATSE Observations
  77. GRB 990506, optical observations
  78. GRB 990506, Optical Observations
  79. GRB 990506 optical observations
  80. GRB 990506 optical observations
  81. GRB 990506, optical observations
  82. GRB990506 observation plan
  83. GRB 990506: Limits on the possible optical transient
  84. GRB 990506, armchair astronomy
  85. GRB 990506, optical observations from +1 to +3 hours
  86. GRB 990506, optical observations
  87. GRB990506 observation plan
  88. New IPN/RXTE error box for GRB990506
  89. IPN localization for GRB990506
  90. GRB 970228: Redshift and properties of the host galaxy
  91. GRB981220 VLBA observations
  92. GRB990321 REFINED IPN ANNULUS
  93. GRB990323 PRECISE IPN POSITION
  94. GRB 990316 Optical Observations
  95. GRB 990316, Radio observations
  96. GRB 990316, Optical observations
  97. GRB990316, Optical observations
  98. GRB 990316 optical observations
  99. GRB990316: simultaneous optical observation
  100. GRB990308 not a new SGR

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