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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"

32494 results found.

  1. IPN localization of BATSE #7766 (GRB990915)
  2. GRB990907: BeppoSAX follow up and X-ray afterglow
  3. GRB990907 and 990908
  4. IPN localization of GRB990907
  5. GRB 990712 Late Optical Decay and Host Galaxy
  6. GRB 990712, Optical Observation
  7. GRB990806 BeppoSAX follow up
  8. GRB990806: BATSE Observations
  9. GRB 990806 Optical observations
  10. Optical Observations of GRB990806
  11. GRB 990806, Optical Observations
  12. GRB 990806, optical observations
  13. GRB 990806, Optical Observations
  14. GRB990806 UBVRIJHK observations
  15. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  16. VLT spectrum of GRB990712
  17. GRB 990712
  18. Late-time HST/STIS Observations of GRB 990510
  19. BeppoSAX NFI Observation of GRB990705
  20. BeppoSAX NFI Observation of GRB990705
  21. Updated Astrometry for the IR Counterpart of GRB990705
  22. GRB 990705, R-band observations
  23. Updated IPN localization of GRB990705
  24. IPN localization of GRB990704
  25. IPN localization of GRB990705
  26. Infrared and Optical Observations of GRB990705
  27. GRB 990705, radio observations
  28. GRB990704: SAX-NFI results summary
  29. GRB990704 radio and optical observations
  30. GRB 990704 X-ray Observations
  31. GRB 990704 Optical Observations
  32. GRB 990704, optical observations
  33. GRB990704
  34. GRB990704
  35. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  36. GRB990704, optical observations
  37. GRB990704: possible X-ray afterglow
  38. Identification of a possible optical counterpart for GRB990704
  39. GRB990704
  40. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  41. Optical Observations of GRB990627
  42. GRB 990627, radio observations
  43. GRB990627: BeppoSAX-WFC final location
  44. GRB 990506 - clarification to GCN 352
  45. GRB 990506 - Optical Observations
  46. Optical Observations of GRB 990506
  47. GRB 990506 Radio Transient
  48. GRB990527 Optical Observations
  49. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  50. Late Afterglows of GRBs 990510, 990123
  51. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  52. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  53. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  54. GRB 990506 optical observation
  55. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  56. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  57. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  58. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  59. radio observations of X-ray/GRB transient field
  60. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  61. Optical report on X-ray/GRB transient
  62. radio detection of X-ray/GRB transient
  63. BeppoSAX: A new fast X-ray transient
  64. GRB 990510: optical observations
  65. GRB990510, VI observations
  66. GRB 990506 R band observations
  67. GRB990510: X-ray afterglow
  68. VLT spectrum of GRB990510
  69. GRB 990510: Broad Band Break
  70. GRB 990510: BATSE Observations
  71. GRB990510: optical observation
  72. GRB 990510 Optical Observations
  73. GRB 990510, BVI photometry
  74. GRB 990510 optical observations
  75. GRB990510 optical observations
  76. GRB990510
  77. GRB 990510 optical observations
  78. GRB 990510 optical observations
  79. Galactic extinction towards GRB 990510
  80. IPN localization of GRB990510
  81. GRB 990506 Radio Observations
  82. GRB 990506: BATSE Observations
  83. GRB 990506, optical observations
  84. GRB 990506, Optical Observations
  85. GRB 990506 optical observations
  86. GRB 990506 optical observations
  87. GRB 990506, optical observations
  88. GRB990506 observation plan
  89. GRB 990506: Limits on the possible optical transient
  90. GRB 990506, armchair astronomy
  91. GRB 990506, optical observations from +1 to +3 hours
  92. GRB 990506, optical observations
  93. GRB990506 observation plan
  94. New IPN/RXTE error box for GRB990506
  95. IPN localization for GRB990506
  96. GRB 970228: Redshift and properties of the host galaxy
  97. GRB981220 VLBA observations
  98. GRB990321 REFINED IPN ANNULUS
  99. GRB990323 PRECISE IPN POSITION
  100. GRB 990316 Optical Observations

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