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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"

20388 results found.

  1. GRB990907 and 990908
  2. GRB 990712 Late Optical Decay and Host Galaxy
  3. GRB 990712, Optical Observation
  4. GRB990806 BeppoSAX follow up
  5. GRB 990806 Optical observations
  6. GRB 990806, optical observations
  7. GRB 990806, Optical Observations
  8. GRB 990712 Optical Observations
  9. GRB 990712
  10. Late-time HST/STIS Observations of GRB 990510
  11. BeppoSAX NFI Observation of GRB990705
  12. BeppoSAX NFI Observation of GRB990705
  13. GRB 990705, R-band observations
  14. GRB990704: SAX-NFI results summary
  15. GRB990704 radio and optical observations
  16. GRB990704
  17. GRB990704, optical observations
  18. GRB990704
  19. Refined BeppoSAX-WFC position of GRB990704
  20. GRB990704: BeppoSAX detection
  21. Late-time HST/STIS Observation of GRB 990123
  22. Optical Observations of GRB 990506
  23. GRB990527 Optical Observations
  24. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  25. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  26. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  27. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  28. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  29. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  30. radio observations of X-ray/GRB transient field
  31. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  32. Optical report on X-ray/GRB transient
  33. GRB 990510: optical linear polarization
  34. GRB 990510: optical observations
  35. GRB990510, VI observations
  36. GRB 990510: Broad Band Break
  37. GRB 990510: BATSE Observations
  38. GRB 990510 optical observations
  39. IPN localization of GRB990510
  40. GRB 990506 Radio Observations
  41. GRB 990123, optical monitoring
  42. GRB 990506: BATSE Observations
  43. GRB 990506, optical observations
  44. GRB 990506, Optical Observations
  45. GRB 990506 optical observations
  46. GRB 990506, optical observations
  47. GRB 990506, optical observations from +1 to +3 hours
  48. GRB 990506, optical observations
  49. GRB990506 observation plan
  50. IPN localization for GRB990506
  51. GRB 990316 Optical Observations
  52. GRB990316, Optical observations
  53. GRB 990316 optical observations
  54. GRB990316: simultaneous optical observation
  55. ASM/IPN error box for GRB 990308 (BATSE #7457)
  56. GRB990308, Possible new SGR~0209+70
  57. GRB 990123, Field Photometry
  58. GRB 990217 Optical Observations
  59. BATSE Flight Anomaly
  60. GRB990123 observations
  61. GRB990123, Optical Observation
  62. GRB 990123: Discovery of the Probable Host Galaxy
  63. GRB19990123 observations
  64. GRB 990123: BVRI standards in the field
  65. GRB 990123: Updated Keck Spectroscopy Results
  66. GRB981220, field photometry
  67. GRB990123, Optical observation
  68. GRB990123, 15-GHz limits
  69. GRB 990123: New Constraints on Possible Foreground Galaxies
  70. GRB990123 Optical Observations
  71. GRB990123, Probability of gravitational lensing
  72. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  73. GRB990123, Preliminary Lens Search Results
  74. Search for Potential Images of GRB 990123
  75. GRB990123, Optical BVRI Observations
  76. GRB 990123: near-infrared observations.
  77. GRB990123, OSSE observations
  78. GRB990123: NIR Observation
  79. "GRB 990123: New BV Observations"
  80. GRB 990123: BATSE Observations
  81. GRB 990123: New Optical Observations, Decay Measure
  82. GRB 990123 Optical Follow-Up
  83. GRB 990123: Possible Gravitationally Lensed Burst?
  84. GRB990123, optical observation
  85. GRB 990123 optical observations
  86. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  87. GRB990123 optical observations
  88. GRB 990123 r-band photometry
  89. GRB 990123 Optical Follow-up
  90. GRB990123 Optical Observation
  91. Possible identification of SN1999E with GRB980910
  92. Optical Observations of GRB 981220
  93. GRB 981226: radio variable
  94. GRB 981226 Optical Observations
  95. GRB981226 Optical Observations
  96. GRB981226 BeppoSAX follow up
  97. GRB 981226 radio observations
  98. GRB 981226
  99. GRB 981226 optical observations
  100. radio observations of GRB 981226

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