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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"

28092 results found.

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

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