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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"

36131 results found.

  1. Optical Observations of GRB990806
  2. GRB 990806, Optical Observations
  3. GRB 990806, optical observations
  4. GRB 990806, Optical Observations
  5. GRB990806 UBVRIJHK observations
  6. BeppoSAX ALERT GRB990806: Summer GRB
  7. GRB 990712 Optical Observations
  8. GRB990705: No Evidence for Neutrino Signal
  9. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  10. VLT spectrum of GRB990712
  11. GRB 990712
  12. Late-time HST/STIS Observations of GRB 990510
  13. Refined BeppoSAX-WFC position of GRB990712
  14. GRB 990705, R-band observations
  15. Updated IPN localization of GRB990705
  16. IPN localization of GRB990704
  17. IPN localization of GRB990705
  18. Infrared and Optical Observations of GRB990705
  19. GRB 990705, radio observations
  20. GRB990704 radio and optical observations
  21. GRB 990704 X-ray Observations
  22. GRB 990704 Optical Observations
  23. GRB 990704, optical observations
  24. GRB990704
  25. GRB990705: Intriguing Positional Coincidences
  26. GRB990704
  27. GRB990704, optical observations
  28. Identification of a possible optical counterpart for GRB990704
  29. GRB990704
  30. Refined BeppoSAX-WFC position of GRB990704
  31. GRB990704: BeppoSAX detection
  32. Optical Observations of GRB990627
  33. GRB 990627, radio observations
  34. GRB990627: BeppoSAX-WFC final location
  35. BeppoSAX: GRB990625
  36. Late-time HST/STIS Observation of GRB 990123
  37. GRB 990506 - clarification to GCN 352
  38. GRB 990506 - Optical Observations
  39. Optical Observations of GRB 990506
  40. GRB 990506 Radio Transient
  41. GRB990527 Optical Observations
  42. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  43. IPN error box for GRB990527
  44. Late Afterglows of GRBs 990510, 990123
  45. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  46. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  47. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  48. GRB 990506 optical observation
  49. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  50. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  51. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  52. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  53. radio observations of X-ray/GRB transient field
  54. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  55. Optical report on X-ray/GRB transient
  56. radio detection of X-ray/GRB transient
  57. BeppoSAX: A new fast X-ray transient
  58. GRB 990510: optical observations
  59. GRB990510: photometric and spectroscopic observations with the VLT
  60. GRB 990510: optical linear polarization
  61. GRB 990510: optical observations
  62. GRB990510, VI observations
  63. GRB 990506 R band observations
  64. GRB990510: X-ray afterglow
  65. GRB 990510: optical observation
  66. VLT spectrum of GRB990510
  67. GRB 990510: Broad Band Break
  68. GRB 990510: BATSE Observations
  69. GRB 990510 Optical Observations
  70. GRB 990510, BVI photometry
  71. GRB 990510 optical observations
  72. GRB 990510: BeppoSAX/GRBM observations
  73. GRB990510 optical observations
  74. GRB 990510 optical observations
  75. GRB 990510 optical observations
  76. Galactic extinction towards GRB 990510
  77. GRB 990510 optical observations
  78. IPN localization of GRB990510
  79. GRB 990506 Radio Observations
  80. GRB 990123, optical monitoring
  81. GRB 990506: BATSE Observations
  82. GRB 990506, optical observations
  83. GRB 990510: Final BeppoSAX-WFC Coordinates
  84. GRB 990506, Optical Observations
  85. GRB 990506 optical observations
  86. GRB 990506 optical observations
  87. GRB 990506, optical observations
  88. GRB990506 observation plan
  89. Refined IPN error box for GRB990506
  90. GRB 990506: Limits on the possible optical transient
  91. GRB 990506, armchair astronomy
  92. GRB 990506, optical observations from +1 to +3 hours
  93. GRB 990506, optical observations
  94. GRB990506 observation plan
  95. New IPN/RXTE error box for GRB990506
  96. IPN localization for GRB990506
  97. GRB 970228: Redshift and properties of the host galaxy
  98. IPN localization of GRB990427
  99. GRB981220 VLBA observations
  100. GRB990321 REFINED IPN ANNULUS

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