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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"

32497 results found.

  1. GRB 990907 optical observations
  2. Optical Observations of GRB990907
  3. IPN error box for GRB990915 (=BATSE 7766)
  4. IPN localization of BATSE #7766 (GRB990915)
  5. GRB990907: BeppoSAX follow up and X-ray afterglow
  6. GRB990907 and 990908
  7. IPN localization of GRB990907
  8. GRB 990712 Late Optical Decay and Host Galaxy
  9. GRB 990712, Optical Observation
  10. GRB990806 BeppoSAX follow up
  11. GRB990806: BATSE Observations
  12. GRB 990806 Optical observations
  13. Optical Observations of GRB990806
  14. GRB 990806, Optical Observations
  15. GRB 990806, optical observations
  16. GRB 990806, Optical Observations
  17. GRB990806 UBVRIJHK observations
  18. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  19. VLT spectrum of GRB990712
  20. GRB 990712
  21. Late-time HST/STIS Observations of GRB 990510
  22. BeppoSAX NFI Observation of GRB990705
  23. BeppoSAX NFI Observation of GRB990705
  24. Updated Astrometry for the IR Counterpart of GRB990705
  25. GRB 990705, R-band observations
  26. Updated IPN localization of GRB990705
  27. IPN localization of GRB990704
  28. IPN localization of GRB990705
  29. Infrared and Optical Observations of GRB990705
  30. GRB 990705, radio observations
  31. GRB990704: SAX-NFI results summary
  32. GRB990704 radio and optical observations
  33. GRB 990704 X-ray Observations
  34. GRB 990704 Optical Observations
  35. GRB 990704, optical observations
  36. GRB990704
  37. GRB990704
  38. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  39. GRB990704, optical observations
  40. GRB990704: possible X-ray afterglow
  41. Identification of a possible optical counterpart for GRB990704
  42. GRB990704
  43. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  44. Optical Observations of GRB990627
  45. GRB 990627, radio observations
  46. GRB990627: BeppoSAX-WFC final location
  47. GRB 990506 - clarification to GCN 352
  48. GRB 990506 - Optical Observations
  49. Optical Observations of GRB 990506
  50. GRB 990506 Radio Transient
  51. GRB990527 Optical Observations
  52. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  53. Late Afterglows of GRBs 990510, 990123
  54. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  55. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  56. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  57. GRB 990506 optical observation
  58. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  59. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  60. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  61. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  62. radio observations of X-ray/GRB transient field
  63. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  64. Optical report on X-ray/GRB transient
  65. radio detection of X-ray/GRB transient
  66. BeppoSAX: A new fast X-ray transient
  67. GRB 990510: optical observations
  68. GRB990510, VI observations
  69. GRB 990506 R band observations
  70. GRB990510: X-ray afterglow
  71. VLT spectrum of GRB990510
  72. GRB 990510: Broad Band Break
  73. GRB 990510: BATSE Observations
  74. GRB990510: optical observation
  75. GRB 990510 Optical Observations
  76. GRB 990510, BVI photometry
  77. GRB 990510 optical observations
  78. GRB990510 optical observations
  79. GRB990510
  80. GRB 990510 optical observations
  81. GRB 990510 optical observations
  82. Galactic extinction towards GRB 990510
  83. IPN localization of GRB990510
  84. GRB 990506 Radio Observations
  85. GRB 990506: BATSE Observations
  86. GRB 990506, optical observations
  87. GRB 990506, Optical Observations
  88. GRB 990506 optical observations
  89. GRB 990506 optical observations
  90. GRB 990506, optical observations
  91. GRB990506 observation plan
  92. GRB 990506: Limits on the possible optical transient
  93. GRB 990506, armchair astronomy
  94. GRB 990506, optical observations from +1 to +3 hours
  95. GRB 990506, optical observations
  96. GRB990506 observation plan
  97. New IPN/RXTE error box for GRB990506
  98. IPN localization for GRB990506
  99. GRB 970228: Redshift and properties of the host galaxy
  100. GRB981220 VLBA observations

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