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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"

32133 results found.

  1. GRB 990712, Optical Observation
  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. BeppoSAX ALERT GRB990806: Summer GRB
  10. GRB 990712 Optical Observations
  11. GRB990705: No Evidence for Neutrino Signal
  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. Refined BeppoSAX-WFC position of GRB990712
  17. GRB 990705, R-band observations
  18. Updated IPN localization of GRB990705
  19. IPN localization of GRB990704
  20. IPN localization of GRB990705
  21. Infrared and Optical Observations of GRB990705
  22. GRB 990705, radio observations
  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. GRB990705: Intriguing Positional Coincidences
  29. GRB990704
  30. GRB990704, optical observations
  31. Identification of a possible optical counterpart for GRB990704
  32. GRB990704
  33. Refined BeppoSAX-WFC position of GRB990704
  34. GRB990704: BeppoSAX detection
  35. Optical Observations of GRB990627
  36. GRB 990627, radio observations
  37. GRB990627: BeppoSAX-WFC final location
  38. BeppoSAX: GRB990625
  39. Late-time HST/STIS Observation of GRB 990123
  40. GRB 990506 - clarification to GCN 352
  41. GRB 990506 - Optical Observations
  42. Optical Observations of GRB 990506
  43. GRB 990506 Radio Transient
  44. GRB990527 Optical Observations
  45. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  46. IPN error box for GRB990527
  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: photometric and spectroscopic observations with the VLT
  63. GRB 990510: optical linear polarization
  64. GRB 990510: optical observations
  65. GRB990510, VI observations
  66. GRB 990506 R band observations
  67. GRB990510: X-ray afterglow
  68. GRB 990510: optical observation
  69. VLT spectrum of GRB990510
  70. GRB 990510: Broad Band Break
  71. GRB 990510: BATSE Observations
  72. GRB 990510 Optical Observations
  73. GRB 990510, BVI photometry
  74. GRB 990510 optical observations
  75. GRB 990510: BeppoSAX/GRBM observations
  76. GRB990510 optical observations
  77. GRB 990510 optical observations
  78. GRB 990510 optical observations
  79. Galactic extinction towards GRB 990510
  80. GRB 990510 optical observations
  81. IPN localization of GRB990510
  82. GRB 990506 Radio Observations
  83. GRB 990123, optical monitoring
  84. GRB 990506: BATSE Observations
  85. GRB 990506, optical observations
  86. GRB 990510: Final BeppoSAX-WFC Coordinates
  87. GRB 990506, Optical Observations
  88. GRB 990506 optical observations
  89. GRB 990506 optical observations
  90. GRB 990506, optical observations
  91. GRB990506 observation plan
  92. Refined IPN error box for GRB990506
  93. GRB 990506: Limits on the possible optical transient
  94. GRB 990506, armchair astronomy
  95. GRB 990506, optical observations from +1 to +3 hours
  96. GRB 990506, optical observations
  97. GRB990506 observation plan
  98. New IPN/RXTE error box for GRB990506
  99. IPN localization for GRB990506
  100. GRB 970228: Redshift and properties of the host galaxy

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