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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"

25840 results found.

  1. IPN localization of GRB991014
  2. GRB 990907 optical observations
  3. Optical Observations of GRB990907
  4. GRB990907: BeppoSAX follow up and X-ray afterglow
  5. GRB990907 and 990908
  6. IPN localization of GRB990907
  7. GRB 990712, Optical Observation
  8. GRB990806 BeppoSAX follow up
  9. GRB990806: BATSE Observations
  10. GRB 990806 Optical observations
  11. GRB 990806, Optical Observations
  12. GRB 990806, optical observations
  13. GRB 990806, Optical Observations
  14. GRB990806 UBVRIJHK observations
  15. GRB990806: possible X-ray afterglow, BeppoSAX
  16. GRB 990712 Optical Observations
  17. GRB 990712
  18. Late-time HST/STIS Observations of GRB 990510
  19. Refined BeppoSAX-WFC position of GRB990712
  20. BeppoSAX NFI Observation of GRB990705
  21. BeppoSAX NFI Observation of GRB990705
  22. GRB 990705, R-band observations
  23. Updated IPN localization of GRB990705
  24. IPN localization of GRB990704
  25. IPN localization of GRB990705
  26. Infrared and Optical Observations of GRB990705
  27. GRB 990705, radio observations
  28. GRB990704: SAX-NFI results summary
  29. GRB990704 radio and optical observations
  30. BeppoSAX GRB990705: possible X-ray afterglow
  31. GRB 990704 X-ray Observations
  32. GRB990704
  33. GRB990704, optical observations
  34. Late-time HST/STIS Observation of GRB 990123
  35. Optical Observations of GRB 990506
  36. GRB990527 Optical Observations
  37. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  38. IPN error box for GRB990527
  39. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  40. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  41. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  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. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  46. radio observations of X-ray/GRB transient field
  47. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  48. Optical report on X-ray/GRB transient
  49. BeppoSAX: A new fast X-ray transient
  50. GRB990510: photometric and spectroscopic observations with the VLT
  51. GRB 990510: optical linear polarization
  52. GRB 990510: optical observations
  53. GRB990510, VI observations
  54. GRB 990510: Broad Band Break
  55. GRB 990510: BATSE Observations
  56. GRB990510: optical observation
  57. GRB 990510: BeppoSAX/GRBM observations
  58. GRB990510 optical observations
  59. GRB 990510 optical observations
  60. GRB 990510 optical observations
  61. GRB 990506 Radio Observations
  62. GRB 990123, optical monitoring
  63. GRB 990506: BATSE Observations
  64. GRB 990506, optical observations
  65. GRB 990506, Optical Observations
  66. GRB 990506 optical observations
  67. GRB 990506, optical observations
  68. GRB 990506, optical observations from +1 to +3 hours
  69. GRB 990506, optical observations
  70. GRB990506 observation plan
  71. GRB 990316 Optical Observations
  72. GRB 990316, Radio observations
  73. GRB 990316, Optical observations
  74. GRB990316, Optical observations
  75. GRB 990316 optical observations
  76. GRB990316: simultaneous optical observation
  77. GRB990316 - Optical null results
  78. ASM/IPN error box for GRB 990308 (BATSE #7457)
  79. GRB 990308a and GRB 990308b
  80. GRB990308 (Trig. 7457), optical observations
  81. GRB990308, Possible new SGR~0209+70
  82. GRB 990123, Field Photometry
  83. GRB 990217 Optical Observations
  84. BATSE Flight Anomaly
  85. GRB990217: BeppoSAX/GRBM data
  86. GRB990123 observations
  87. GRB990217 Optical observation
  88. GRB990123, Optical Observation
  89. GRB 990123: Discovery of the Probable Host Galaxy
  90. GRB19990123 observations
  91. GRB 990123: BVRI standards in the field
  92. GRB981220, field photometry
  93. GRB990123, Optical observation
  94. GRB990123, 15-GHz limits
  95. GRB 990123: New Constraints on Possible Foreground Galaxies
  96. GRB990123 Optical Observations
  97. GRB990123, Probability of gravitational lensing
  98. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  99. GRB 990123: Continued Radio Observations
  100. GRB990123, Preliminary Lens Search Results

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