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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"

36016 results found.

  1. Updated IPN localization of GRB990705
  2. IPN localization of GRB990704
  3. IPN localization of GRB990705
  4. Infrared and Optical Observations of GRB990705
  5. GRB 990705, radio observations
  6. GRB990704 radio and optical observations
  7. GRB 990704 X-ray Observations
  8. GRB 990704 Optical Observations
  9. GRB 990704, optical observations
  10. GRB990704
  11. GRB990705: Intriguing Positional Coincidences
  12. GRB990704
  13. GRB990704, optical observations
  14. Identification of a possible optical counterpart for GRB990704
  15. GRB990704
  16. Refined BeppoSAX-WFC position of GRB990704
  17. GRB990704: BeppoSAX detection
  18. Optical Observations of GRB990627
  19. GRB 990627, radio observations
  20. GRB990627: BeppoSAX-WFC final location
  21. BeppoSAX: GRB990625
  22. Late-time HST/STIS Observation of GRB 990123
  23. GRB 990506 - clarification to GCN 352
  24. GRB 990506 - Optical Observations
  25. Optical Observations of GRB 990506
  26. GRB 990506 Radio Transient
  27. GRB990527 Optical Observations
  28. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  29. IPN error box for GRB990527
  30. Late Afterglows of GRBs 990510, 990123
  31. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  32. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  33. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  34. GRB 990506 optical observation
  35. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  36. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  37. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  38. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  39. radio observations of X-ray/GRB transient field
  40. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  41. Optical report on X-ray/GRB transient
  42. radio detection of X-ray/GRB transient
  43. BeppoSAX: A new fast X-ray transient
  44. GRB 990510: optical observations
  45. GRB990510: photometric and spectroscopic observations with the VLT
  46. GRB 990510: optical linear polarization
  47. GRB 990510: optical observations
  48. GRB990510, VI observations
  49. GRB 990506 R band observations
  50. GRB990510: X-ray afterglow
  51. GRB 990510: optical observation
  52. VLT spectrum of GRB990510
  53. GRB 990510: Broad Band Break
  54. GRB 990510: BATSE Observations
  55. GRB 990510 Optical Observations
  56. GRB 990510, BVI photometry
  57. GRB 990510 optical observations
  58. GRB 990510: BeppoSAX/GRBM observations
  59. GRB990510 optical observations
  60. GRB 990510 optical observations
  61. GRB 990510 optical observations
  62. Galactic extinction towards GRB 990510
  63. GRB 990510 optical observations
  64. IPN localization of GRB990510
  65. GRB 990506 Radio Observations
  66. GRB 990123, optical monitoring
  67. GRB 990506: BATSE Observations
  68. GRB 990506, optical observations
  69. GRB 990510: Final BeppoSAX-WFC Coordinates
  70. GRB 990506, Optical Observations
  71. GRB 990506 optical observations
  72. GRB 990506 optical observations
  73. GRB 990506, optical observations
  74. GRB990506 observation plan
  75. Refined IPN error box for GRB990506
  76. GRB 990506: Limits on the possible optical transient
  77. GRB 990506, armchair astronomy
  78. GRB 990506, optical observations from +1 to +3 hours
  79. GRB 990506, optical observations
  80. GRB990506 observation plan
  81. New IPN/RXTE error box for GRB990506
  82. IPN localization for GRB990506
  83. GRB 970228: Redshift and properties of the host galaxy
  84. IPN localization of GRB990427
  85. GRB981220 VLBA observations
  86. GRB990321 REFINED IPN ANNULUS
  87. GRB990323 PRECISE IPN POSITION
  88. GRB990321 IPN TRIANGULATION
  89. GRB 990316 Optical Observations
  90. GRB 990316, Radio observations
  91. GRB 990316, Optical observations
  92. GRB990316, Optical observations
  93. GRB 990316 optical observations
  94. GRB990316: simultaneous optical observation
  95. ASM/IPN error box for GRB 990308 (BATSE #7457)
  96. GRB990308 not a new SGR
  97. GRB 990308a and GRB 990308b
  98. GRB990308 (Trig. 7457), optical observations
  99. GRB981220, IPN localization
  100. GRB 981220, radio observations

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