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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"

44392 results found.

  1. GRB 990712 Optical Observations
  2. GRB990705: No Evidence for Neutrino Signal
  3. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  4. VLT spectrum of GRB990712
  5. GRB 990712
  6. Late-time HST/STIS Observations of GRB 990510
  7. Refined BeppoSAX-WFC position of GRB990712
  8. BeppoSAX NFI Observation of GRB990705
  9. BeppoSAX NFI Observation of GRB990705
  10. Updated Astrometry for the IR Counterpart of GRB990705
  11. GRB 990705, R-band observations
  12. Updated IPN localization of GRB990705
  13. IPN localization of GRB990704
  14. IPN localization of GRB990705
  15. Infrared and Optical Observations of GRB990705
  16. GRB 990705, radio observations
  17. GRB990704: SAX-NFI results summary
  18. GRB990704 radio and optical observations
  19. BeppoSAX GRB990705: possible X-ray afterglow
  20. GRB 990704 X-ray Observations
  21. GRB 990704 Optical Observations
  22. GRB 990704, optical observations
  23. GRB990704
  24. GRB990705: Intriguing Positional Coincidences
  25. GRB990704
  26. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  27. GRB990704, optical observations
  28. GRB990704: possible X-ray afterglow
  29. Identification of a possible optical counterpart for GRB990704
  30. GRB990704
  31. Refined BeppoSAX-WFC position of GRB990704
  32. GRB990704: BeppoSAX detection
  33. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  34. Optical Observations of GRB990627
  35. GRB 990627, radio observations
  36. GRB990627: BeppoSAX-WFC final location
  37. BeppoSAX: GRB990625
  38. Late-time HST/STIS Observation of GRB 990123
  39. GRB 990506 - clarification to GCN 352
  40. GRB 990506 - Optical Observations
  41. Optical Observations of GRB 990506
  42. GRB 990506 Radio Transient
  43. GRB990527 Optical Observations
  44. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  45. IPN error box for GRB990527
  46. Late Afterglows of GRBs 990510, 990123
  47. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  48. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  49. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  50. GRB 990506 optical observation
  51. X-ray/GRB 1SAX J0835.9+5118, 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. radio observations of X-ray/GRB transient field
  56. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  57. Optical report on X-ray/GRB transient
  58. radio detection of X-ray/GRB transient
  59. BeppoSAX: A new fast X-ray transient
  60. GRB 990510: optical observations
  61. GRB990510: photometric and spectroscopic observations with the VLT
  62. GRB 990510: optical linear polarization
  63. GRB 990510: optical observations
  64. GRB990510, VI observations
  65. GRB 990506 R band observations
  66. GRB990510: X-ray afterglow
  67. GRB 990510: optical observation
  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. GRB 990510: BeppoSAX/GRBM observations
  76. GRB990510 optical observations
  77. GRB990510
  78. GRB 990510 optical observations
  79. GRB 990510 optical observations
  80. Galactic extinction towards GRB 990510
  81. GRB990510: NFI X-ray source
  82. GRB 990510 optical observations
  83. IPN localization of GRB990510
  84. GRB 990506 Radio Observations
  85. GRB 990123, optical monitoring
  86. GRB 990506: BATSE Observations
  87. GRB 990506, optical observations
  88. GRB 990510: Final BeppoSAX-WFC Coordinates
  89. GRB 990506, Optical Observations
  90. GRB 990506 optical observations
  91. GRB 990506 optical observations
  92. GRB 990506, optical observations
  93. GRB990506 observation plan
  94. Refined IPN error box for GRB990506
  95. GRB 990506: Limits on the possible optical transient
  96. GRB 990506, armchair astronomy
  97. GRB 990506, optical observations from +1 to +3 hours
  98. GRB 990506, optical observations
  99. GRB990506 Optical observations
  100. New IPN/RXTE error box for GRB990506

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