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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"

44294 results found.

  1. GRB990806: possible X-ray afterglow, BeppoSAX
  2. BeppoSAX ALERT GRB990806: Summer GRB
  3. GRB 990712 Optical Observations
  4. GRB990705: No Evidence for Neutrino Signal
  5. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  6. VLT spectrum of GRB990712
  7. GRB 990712
  8. Late-time HST/STIS Observations of GRB 990510
  9. Refined BeppoSAX-WFC position of GRB990712
  10. BeppoSAX NFI Observation of GRB990705
  11. BeppoSAX NFI Observation of GRB990705
  12. Updated Astrometry for the IR Counterpart of GRB990705
  13. GRB 990705, R-band observations
  14. Updated IPN localization of GRB990705
  15. IPN localization of GRB990704
  16. IPN localization of GRB990705
  17. Infrared and Optical Observations of GRB990705
  18. GRB 990705, radio observations
  19. GRB990704: SAX-NFI results summary
  20. GRB990704 radio and optical observations
  21. BeppoSAX GRB990705: possible X-ray afterglow
  22. GRB 990704 X-ray Observations
  23. GRB 990704 Optical Observations
  24. GRB 990704, optical observations
  25. GRB990704
  26. GRB990705: Intriguing Positional Coincidences
  27. GRB990704
  28. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  29. GRB990704, optical observations
  30. GRB990704: possible X-ray afterglow
  31. Identification of a possible optical counterpart for GRB990704
  32. GRB990704
  33. Refined BeppoSAX-WFC position of GRB990704
  34. GRB990704: BeppoSAX detection
  35. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  36. Optical Observations of GRB990627
  37. GRB 990627, radio observations
  38. GRB990627: BeppoSAX-WFC final location
  39. BeppoSAX: GRB990625
  40. Late-time HST/STIS Observation of GRB 990123
  41. GRB 990506 - clarification to GCN 352
  42. GRB 990506 - Optical Observations
  43. Optical Observations of GRB 990506
  44. GRB 990506 Radio Transient
  45. GRB990527 Optical Observations
  46. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  47. IPN error box for GRB990527
  48. Late Afterglows of GRBs 990510, 990123
  49. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  50. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  51. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  52. GRB 990506 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. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  57. radio observations of X-ray/GRB transient field
  58. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  59. Optical report on X-ray/GRB transient
  60. radio detection of X-ray/GRB transient
  61. BeppoSAX: A new fast X-ray transient
  62. GRB 990510: optical observations
  63. GRB990510: photometric and spectroscopic observations with the VLT
  64. GRB 990510: optical linear polarization
  65. GRB 990510: optical observations
  66. GRB990510, VI observations
  67. GRB 990506 R band observations
  68. GRB990510: X-ray afterglow
  69. GRB 990510: optical observation
  70. VLT spectrum of GRB990510
  71. GRB 990510: Broad Band Break
  72. GRB 990510: BATSE Observations
  73. GRB990510: optical observation
  74. GRB 990510 Optical Observations
  75. GRB 990510, BVI photometry
  76. GRB 990510 optical observations
  77. GRB 990510: BeppoSAX/GRBM observations
  78. GRB990510 optical observations
  79. GRB990510
  80. GRB 990510 optical observations
  81. GRB 990510 optical observations
  82. Galactic extinction towards GRB 990510
  83. GRB990510: NFI X-ray source
  84. GRB 990510 optical observations
  85. IPN localization of GRB990510
  86. GRB 990506 Radio Observations
  87. GRB 990123, optical monitoring
  88. GRB 990506: BATSE Observations
  89. GRB 990506, optical observations
  90. GRB 990510: Final BeppoSAX-WFC Coordinates
  91. GRB 990506, Optical Observations
  92. GRB 990506 optical observations
  93. GRB 990506 optical observations
  94. GRB 990506, optical observations
  95. GRB990506 observation plan
  96. Refined IPN error box for GRB990506
  97. GRB 990506: Limits on the possible optical transient
  98. GRB 990506, armchair astronomy
  99. GRB 990506, optical observations from +1 to +3 hours
  100. GRB 990506, optical observations

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