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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"

15556 results found.

  1. GRB 991014, Optical Observations
  2. GRB 991014, Optical Observations
  3. GRB 991014, optical observations
  4. Super-LOTIS optical observation of GRB991014
  5. GRB 990915 optical observations
  6. GRB 990907 optical observations
  7. Optical Observations of GRB990907
  8. GRB 990712 Late Optical Decay and Host Galaxy
  9. GRB 990712, Optical Observation
  10. GRB 990806 Optical observations
  11. Optical Observations of GRB990806
  12. GRB 990806, Optical Observations
  13. GRB 990806, optical observations
  14. GRB 990806, Optical Observations
  15. GRB990806 UBVRIJHK observations
  16. GRB 990712 Optical Observations
  17. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  18. VLT spectrum of GRB990712
  19. GRB 990712
  20. GRB 990705, R-band observations
  21. IPN localization of GRB990704
  22. Infrared and Optical Observations of GRB990705
  23. GRB990704 radio and optical observations
  24. GRB 990704 Optical Observations
  25. GRB 990704, optical observations
  26. GRB990704
  27. GRB990704
  28. GRB990704, optical observations
  29. Identification of a possible optical counterpart for GRB990704
  30. GRB990704
  31. Optical Observations of GRB990627
  32. Late-time HST/STIS Observation of GRB 990123
  33. GRB 990506 - Optical Observations
  34. Optical Observations of GRB 990506
  35. GRB 990506 Radio Transient
  36. GRB990527 Optical Observations
  37. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  38. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  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. GRB 990510: optical observations
  49. GRB990510: photometric and spectroscopic observations with the VLT
  50. GRB 990510: optical linear polarization
  51. GRB 990510: optical observations
  52. GRB990510, VI observations
  53. GRB 990506 R band observations
  54. GRB990510: X-ray afterglow
  55. GRB 990510: optical observation
  56. VLT spectrum of GRB990510
  57. GRB 990510: Broad Band Break
  58. GRB 990510: BATSE Observations
  59. GRB990510: optical observation
  60. GRB 990510 Optical Observations
  61. GRB 990510, BVI photometry
  62. GRB 990510 optical observations
  63. GRB990510 optical observations
  64. GRB990510
  65. GRB 990510 optical observations
  66. GRB 990510 optical observations
  67. Galactic extinction towards GRB 990510
  68. GRB 990510 optical observations
  69. GRB 990123, optical monitoring
  70. GRB 990506, optical observations
  71. GRB 990506, Optical Observations
  72. GRB 990506 optical observations
  73. GRB 990506 optical observations
  74. GRB 990506, optical observations
  75. GRB 990506: Limits on the possible optical transient
  76. GRB 990506, armchair astronomy
  77. GRB 990506, optical observations from +1 to +3 hours
  78. GRB 990506, optical observations
  79. GRB990506 Optical observations
  80. GRB980425 Optical observations of exponential decline at late time
  81. GRB 990316 Optical Observations
  82. GRB 990316, Radio observations
  83. GRB 990316, Optical observations
  84. GRB990316, Optical observations
  85. GRB 990316 optical observations
  86. GRB990316: simultaneous optical observation
  87. GRB990316 - Optical null results
  88. GRB990308 (Trig. 7457), optical observations
  89. GRB 990217 Optical Observations
  90. Optical Observations of GRB990217
  91. GRB990123 observations
  92. GRB990217 Optical observation
  93. GRB990123, Optical Observation
  94. GRB 990123: Discovery of the Probable Host Galaxy
  95. GRB 990123: Reduced HST Images
  96. GRB19990123 observations
  97. GRB 990123: Updated Keck Spectroscopy Results
  98. GRB990123, Optical observation
  99. GRB 990123: New Constraints on Possible Foreground Galaxies
  100. GRB990123 Optical Observations

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