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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"

35423 results found.

  1. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  2. VLT spectrum of GRB990712
  3. GRB 990712
  4. Late-time HST/STIS Observations of GRB 990510
  5. Refined BeppoSAX-WFC position of GRB990712
  6. GRB 990705, R-band observations
  7. Updated IPN localization of GRB990705
  8. IPN localization of GRB990704
  9. IPN localization of GRB990705
  10. Infrared and Optical Observations of GRB990705
  11. GRB 990705, radio observations
  12. GRB990704 radio and optical observations
  13. GRB 990704 X-ray Observations
  14. GRB 990704 Optical Observations
  15. GRB 990704, optical observations
  16. GRB990704
  17. GRB990705: Intriguing Positional Coincidences
  18. GRB990704
  19. GRB990704, optical observations
  20. Identification of a possible optical counterpart for GRB990704
  21. GRB990704
  22. Refined BeppoSAX-WFC position of GRB990704
  23. GRB990704: BeppoSAX detection
  24. Optical Observations of GRB990627
  25. GRB 990627, radio observations
  26. GRB990627: BeppoSAX-WFC final location
  27. BeppoSAX: GRB990625
  28. Late-time HST/STIS Observation of GRB 990123
  29. GRB 990506 - clarification to GCN 352
  30. GRB 990506 - Optical Observations
  31. Optical Observations of GRB 990506
  32. GRB 990506 Radio Transient
  33. GRB990527 Optical Observations
  34. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  35. IPN error box for GRB990527
  36. Late Afterglows of GRBs 990510, 990123
  37. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  38. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  39. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  40. GRB 990506 optical observation
  41. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  42. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  43. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  44. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  45. radio observations of X-ray/GRB transient field
  46. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  47. Optical report on X-ray/GRB transient
  48. radio detection of X-ray/GRB transient
  49. BeppoSAX: A new fast X-ray transient
  50. GRB 990510: optical observations
  51. GRB990510: photometric and spectroscopic observations with the VLT
  52. GRB 990510: optical linear polarization
  53. GRB 990510: optical observations
  54. GRB990510, VI observations
  55. GRB 990506 R band observations
  56. GRB990510: X-ray afterglow
  57. GRB 990510: optical observation
  58. VLT spectrum of GRB990510
  59. GRB 990510: Broad Band Break
  60. GRB 990510: BATSE Observations
  61. GRB 990510 Optical Observations
  62. GRB 990510, BVI photometry
  63. GRB 990510 optical observations
  64. GRB 990510: BeppoSAX/GRBM observations
  65. GRB990510 optical observations
  66. GRB 990510 optical observations
  67. GRB 990510 optical observations
  68. Galactic extinction towards GRB 990510
  69. GRB 990510 optical observations
  70. IPN localization of GRB990510
  71. GRB 990506 Radio Observations
  72. GRB 990123, optical monitoring
  73. GRB 990506: BATSE Observations
  74. GRB 990506, optical observations
  75. GRB 990510: Final BeppoSAX-WFC Coordinates
  76. GRB 990506, Optical Observations
  77. GRB 990506 optical observations
  78. GRB 990506 optical observations
  79. GRB 990506, optical observations
  80. GRB990506 observation plan
  81. Refined IPN error box for GRB990506
  82. GRB 990506: Limits on the possible optical transient
  83. GRB 990506, armchair astronomy
  84. GRB 990506, optical observations from +1 to +3 hours
  85. GRB 990506, optical observations
  86. GRB990506 observation plan
  87. New IPN/RXTE error box for GRB990506
  88. IPN localization for GRB990506
  89. GRB 970228: Redshift and properties of the host galaxy
  90. IPN localization of GRB990427
  91. GRB981220 VLBA observations
  92. GRB990321 REFINED IPN ANNULUS
  93. GRB990323 PRECISE IPN POSITION
  94. GRB990321 IPN TRIANGULATION
  95. GRB 990316 Optical Observations
  96. GRB 990316, Radio observations
  97. GRB 990316, Optical observations
  98. GRB990316, Optical observations
  99. GRB 990316 optical observations
  100. GRB990316: simultaneous optical observation

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