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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"

37518 results found.

  1. Refined BeppoSAX-WFC position of GRB990712
  2. GRB 990705, R-band observations
  3. Updated IPN localization of GRB990705
  4. IPN localization of GRB990704
  5. IPN localization of GRB990705
  6. Infrared and Optical Observations of GRB990705
  7. GRB 990705, radio observations
  8. GRB990704 radio and optical observations
  9. GRB 990704 X-ray Observations
  10. GRB 990704 Optical Observations
  11. GRB 990704, optical observations
  12. GRB990704
  13. GRB990705: Intriguing Positional Coincidences
  14. GRB990704
  15. GRB990704, optical observations
  16. Identification of a possible optical counterpart for GRB990704
  17. GRB990704
  18. Refined BeppoSAX-WFC position of GRB990704
  19. GRB990704: BeppoSAX detection
  20. Optical Observations of GRB990627
  21. GRB 990627, radio observations
  22. GRB990627: BeppoSAX-WFC final location
  23. BeppoSAX: GRB990625
  24. Late-time HST/STIS Observation of GRB 990123
  25. GRB 990506 - clarification to GCN 352
  26. GRB 990506 - Optical Observations
  27. Optical Observations of GRB 990506
  28. GRB 990506 Radio Transient
  29. GRB990527 Optical Observations
  30. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  31. IPN error box for GRB990527
  32. Late Afterglows of GRBs 990510, 990123
  33. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  34. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  35. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  36. GRB 990506 optical observation
  37. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  38. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  39. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  40. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  41. radio observations of X-ray/GRB transient field
  42. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  43. Optical report on X-ray/GRB transient
  44. radio detection of X-ray/GRB transient
  45. BeppoSAX: A new fast X-ray transient
  46. GRB 990510: optical observations
  47. GRB990510: photometric and spectroscopic observations with the VLT
  48. GRB 990510: optical linear polarization
  49. GRB 990510: optical observations
  50. GRB990510, VI observations
  51. GRB 990506 R band observations
  52. GRB990510: X-ray afterglow
  53. GRB 990510: optical observation
  54. VLT spectrum of GRB990510
  55. GRB 990510: Broad Band Break
  56. GRB 990510: BATSE Observations
  57. GRB 990510 Optical Observations
  58. GRB 990510, BVI photometry
  59. GRB 990510 optical observations
  60. GRB 990510: BeppoSAX/GRBM observations
  61. GRB990510 optical observations
  62. GRB 990510 optical observations
  63. GRB 990510 optical observations
  64. Galactic extinction towards GRB 990510
  65. GRB 990510 optical observations
  66. IPN localization of GRB990510
  67. GRB 990506 Radio Observations
  68. GRB 990123, optical monitoring
  69. GRB 990506: BATSE Observations
  70. GRB 990506, optical observations
  71. GRB 990510: Final BeppoSAX-WFC Coordinates
  72. GRB 990506, Optical Observations
  73. GRB 990506 optical observations
  74. GRB 990506 optical observations
  75. GRB 990506, optical observations
  76. GRB990506 observation plan
  77. Refined IPN error box for GRB990506
  78. GRB 990506: Limits on the possible optical transient
  79. GRB 990506, armchair astronomy
  80. GRB 990506, optical observations from +1 to +3 hours
  81. GRB 990506, optical observations
  82. GRB990506 observation plan
  83. New IPN/RXTE error box for GRB990506
  84. IPN localization for GRB990506
  85. GRB 970228: Redshift and properties of the host galaxy
  86. IPN localization of GRB990427
  87. GRB981220 VLBA observations
  88. GRB990321 REFINED IPN ANNULUS
  89. GRB990323 PRECISE IPN POSITION
  90. GRB990321 IPN TRIANGULATION
  91. GRB 990316 Optical Observations
  92. GRB 990316, Radio observations
  93. GRB 990316, Optical observations
  94. GRB990316, Optical observations
  95. GRB 990316 optical observations
  96. GRB990316: simultaneous optical observation
  97. ASM/IPN error box for GRB 990308 (BATSE #7457)
  98. GRB990308 not a new SGR
  99. GRB 990308a and GRB 990308b
  100. GRB990308 (Trig. 7457), optical observations

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