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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"

26193 results found.

  1. GRB990527 Optical Observations
  2. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  3. Late Afterglows of GRBs 990510, 990123
  4. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  5. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  6. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  7. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  8. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  9. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  10. radio observations of X-ray/GRB transient field
  11. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  12. Optical report on X-ray/GRB transient
  13. radio detection of X-ray/GRB transient
  14. BeppoSAX: A new fast X-ray transient
  15. GRB 990510: optical observations
  16. GRB 990510: optical linear polarization
  17. GRB 990510: optical observations
  18. GRB990510: X-ray afterglow
  19. GRB 990510: Broad Band Break
  20. GRB 990510: BATSE Observations
  21. GRB 990510: BeppoSAX/GRBM observations
  22. GRB990510 optical observations
  23. GRB 990510 optical observations
  24. GRB 990506 Radio Observations
  25. GRB 990123, optical monitoring
  26. GRB 990506: BATSE Observations
  27. GRB 990506, optical observations
  28. GRB 990506, Optical Observations
  29. GRB 990506 optical observations
  30. GRB 990506, optical observations
  31. GRB 990506, armchair astronomy
  32. GRB 990506, optical observations from +1 to +3 hours
  33. GRB 990506, optical observations
  34. GRB990506 observation plan
  35. IPN localization for GRB990506
  36. GRB990323 PRECISE IPN POSITION
  37. GRB 990316 Optical Observations
  38. GRB 990316 optical observations
  39. GRB990316: simultaneous optical observation
  40. GRB990316 - Optical null results
  41. GRB990308 not a new SGR
  42. GRB 990308a and GRB 990308b
  43. GRB990308, Possible new SGR~0209+70
  44. GRB 990123, Field Photometry
  45. GRB 990217 Optical Observations
  46. BATSE Flight Anomaly
  47. GRB990217: BeppoSAX/GRBM data
  48. GRB990123 observations
  49. GRB990217 Optical observation
  50. GRB990123, Optical Observation
  51. GRB 990123: Discovery of the Probable Host Galaxy
  52. GRB 990123: Reduced HST Images
  53. GRB19990123 observations
  54. GRB 990123: BVRI standards in the field
  55. GRB981220, field photometry
  56. GRB990123, Optical observation
  57. GRB990123, 15-GHz limits
  58. GRB 990123: New Constraints on Possible Foreground Galaxies
  59. GRB990123 Optical Observations
  60. GRB990123, Probability of gravitational lensing
  61. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  62. GRB990123, Preliminary Lens Search Results
  63. On the Lensing Interpretation of GRB 990123
  64. Search for Potential Images of GRB 990123
  65. Search for Potential Images of GRB 990123
  66. GRB990123, Optical BVRI Observations
  67. GRB 990123: near-infrared observations.
  68. GRB990123, OSSE observations
  69. GRB990123: NIR Observation
  70. GRB990123, ASCA X-ray observation of afterglow
  71. "GRB 990123: New BV Observations"
  72. GRB 990123 Optical Follow-Up
  73. GRB 990123: BATSE Observations
  74. GRB990123 Optical Observations
  75. GRB 990123: New Optical Observations, Decay Measure
  76. GRB 990123 Optical Follow-Up
  77. GRB 990123: Possible Gravitationally Lensed Burst?
  78. GRB990123, optical observation
  79. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  80. GRB990123, Optical observation
  81. GRB 990123: Optical Decay Slope
  82. GRB 990123 r-band photometry
  83. GRB 990123 Optical Follow-up
  84. GRB990123, early optical counterpart detection
  85. GRB990123 Optical Observation
  86. Possible identification of SN1999E with GRB980910
  87. Optical Observations of GRB 981220
  88. GRB 981226: radio variable
  89. GRB981220
  90. GRB981220, Correction to GCN 179
  91. GRB 981220 Optical observations
  92. GRB 981226 Optical Observations
  93. GRB 981220 and GRB 981226, optical observations
  94. GRB981226 Optical Observations
  95. GRB981226 BeppoSAX follow up
  96. GRB 981226
  97. GRB 981226 optical observations
  98. GRB981220 B, R and I band observations
  99. Optical Observations of GRB981226
  100. GRB 981220:Optical Observations

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