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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"

16155 results found.

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

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