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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"

44428 results found.

  1. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  2. GRB 991014, Optical Observations
  3. GRB 991014 - BeppoSAX NFI observations
  4. GRB 991014, Optical Observations
  5. GRB 991014, radio observations
  6. GRB991014 BATSE Observations
  7. GRB 991014, Optical Observations
  8. GRB 991014, optical observations
  9. Super-LOTIS optical observation of GRB991014
  10. IPN/NFI error box for GRB991014
  11. IPN localization of GRB991014 - CORRECTION
  12. IPN localization of GRB991014
  13. BeppoSAX ALERT: GRB991014
  14. GRB 990915 optical observations
  15. GRB 990907 optical observations
  16. Optical Observations of GRB990907
  17. IPN error box for GRB990915 (=BATSE 7766)
  18. IPN localization of BATSE #7766 (GRB990915)
  19. GRB990907: BeppoSAX follow up and X-ray afterglow
  20. GRB990907 and 990908
  21. IPN localization of GRB990907
  22. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  23. GRB990907: refined WFC position
  24. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  25. GRB 990712 Late Optical Decay and Host Galaxy
  26. GRB 990712, Optical Observation
  27. GRB990806 BeppoSAX follow up
  28. GRB990806: BATSE Observations
  29. GRB 990806 Optical observations
  30. Optical Observations of GRB990806
  31. GRB 990806, Optical Observations
  32. GRB 990806, optical observations
  33. GRB 990806, Optical Observations
  34. GRB990806 UBVRIJHK observations
  35. GRB990806: possible X-ray afterglow, BeppoSAX
  36. BeppoSAX ALERT GRB990806: Summer GRB
  37. GRB 990712 Optical Observations
  38. GRB990705: No Evidence for Neutrino Signal
  39. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  40. VLT spectrum of GRB990712
  41. GRB 990712
  42. Late-time HST/STIS Observations of GRB 990510
  43. Refined BeppoSAX-WFC position of GRB990712
  44. BeppoSAX NFI Observation of GRB990705
  45. BeppoSAX NFI Observation of GRB990705
  46. Updated Astrometry for the IR Counterpart of GRB990705
  47. GRB 990705, R-band observations
  48. Updated IPN localization of GRB990705
  49. IPN localization of GRB990704
  50. IPN localization of GRB990705
  51. Infrared and Optical Observations of GRB990705
  52. GRB 990705, radio observations
  53. GRB990704: SAX-NFI results summary
  54. GRB990704 radio and optical observations
  55. BeppoSAX GRB990705: possible X-ray afterglow
  56. GRB 990704 X-ray Observations
  57. GRB 990704 Optical Observations
  58. GRB 990704, optical observations
  59. GRB990704
  60. GRB990705: Intriguing Positional Coincidences
  61. GRB990704
  62. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  63. GRB990704, optical observations
  64. GRB990704: possible X-ray afterglow
  65. Identification of a possible optical counterpart for GRB990704
  66. GRB990704
  67. Refined BeppoSAX-WFC position of GRB990704
  68. GRB990704: BeppoSAX detection
  69. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  70. Optical Observations of GRB990627
  71. GRB 990627, radio observations
  72. GRB990627: BeppoSAX-WFC final location
  73. BeppoSAX: GRB990625
  74. Late-time HST/STIS Observation of GRB 990123
  75. GRB 990506 - clarification to GCN 352
  76. GRB 990506 - Optical Observations
  77. Optical Observations of GRB 990506
  78. GRB 990506 Radio Transient
  79. GRB990527 Optical Observations
  80. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  81. IPN error box for GRB990527
  82. Late Afterglows of GRBs 990510, 990123
  83. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  84. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  85. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  86. GRB 990506 optical observation
  87. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  88. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  89. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  90. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  91. radio observations of X-ray/GRB transient field
  92. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  93. Optical report on X-ray/GRB transient
  94. radio detection of X-ray/GRB transient
  95. BeppoSAX: A new fast X-ray transient
  96. GRB 990510: optical observations
  97. GRB990510: photometric and spectroscopic observations with the VLT
  98. GRB 990510: optical linear polarization
  99. GRB 990510: optical observations
  100. GRB990510, VI observations

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