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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"

44331 results found.

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

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