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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"

24600 results found.

  1. GRB990704
  2. GRB990704, optical observations
  3. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  4. Optical Observations of GRB990627
  5. BeppoSAX: GRB990625
  6. Late-time HST/STIS Observation of GRB 990123
  7. Optical Observations of GRB 990506
  8. GRB990527 Optical Observations
  9. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  10. Late Afterglows of GRBs 990510, 990123
  11. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  12. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  13. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  14. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  15. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  16. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  17. radio observations of X-ray/GRB transient field
  18. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  19. Optical report on X-ray/GRB transient
  20. radio detection of X-ray/GRB transient
  21. BeppoSAX: A new fast X-ray transient
  22. GRB 990510: optical observations
  23. GRB 990510: optical linear polarization
  24. GRB 990510: optical observations
  25. GRB990510: X-ray afterglow
  26. GRB 990510: Broad Band Break
  27. GRB 990510: BATSE Observations
  28. GRB 990510: BeppoSAX/GRBM observations
  29. GRB990510 optical observations
  30. GRB 990510 optical observations
  31. GRB 990506 Radio Observations
  32. GRB 990123, optical monitoring
  33. GRB 990506: BATSE Observations
  34. GRB 990506, optical observations
  35. GRB 990506, Optical Observations
  36. GRB 990506 optical observations
  37. GRB 990506, optical observations
  38. GRB 990506, armchair astronomy
  39. GRB 990506, optical observations from +1 to +3 hours
  40. GRB 990506, optical observations
  41. GRB990506 observation plan
  42. IPN localization for GRB990506
  43. GRB990323 PRECISE IPN POSITION
  44. GRB 990316 Optical Observations
  45. GRB 990316 optical observations
  46. GRB990316: simultaneous optical observation
  47. GRB990316 - Optical null results
  48. GRB990308 not a new SGR
  49. GRB 990308a and GRB 990308b
  50. GRB990308, Possible new SGR~0209+70
  51. GRB 990123, Field Photometry
  52. GRB 990217 Optical Observations
  53. BATSE Flight Anomaly
  54. GRB990217: BeppoSAX/GRBM data
  55. GRB990123 observations
  56. GRB990217 Optical observation
  57. GRB990123, Optical Observation
  58. GRB 990123: Discovery of the Probable Host Galaxy
  59. GRB 990123: Reduced HST Images
  60. GRB19990123 observations
  61. GRB 990123: BVRI standards in the field
  62. GRB981220, field photometry
  63. GRB990123, Optical observation
  64. GRB990123, 15-GHz limits
  65. GRB 990123: New Constraints on Possible Foreground Galaxies
  66. GRB990123 Optical Observations
  67. GRB990123, Probability of gravitational lensing
  68. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  69. GRB990123, Preliminary Lens Search Results
  70. On the Lensing Interpretation of GRB 990123
  71. Search for Potential Images of GRB 990123
  72. Search for Potential Images of GRB 990123
  73. GRB990123, Optical BVRI Observations
  74. GRB 990123: near-infrared observations.
  75. GRB990123, OSSE observations
  76. GRB990123: NIR Observation
  77. GRB990123, ASCA X-ray observation of afterglow
  78. "GRB 990123: New BV Observations"
  79. GRB 990123 Optical Follow-Up
  80. GRB 990123: BATSE Observations
  81. GRB990123 Optical Observations
  82. GRB 990123: New Optical Observations, Decay Measure
  83. GRB 990123 Optical Follow-Up
  84. GRB 990123: Possible Gravitationally Lensed Burst?
  85. GRB990123, optical observation
  86. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  87. GRB990123, Optical observation
  88. GRB 990123: Optical Decay Slope
  89. GRB 990123 r-band photometry
  90. GRB 990123 Optical Follow-up
  91. GRB990123, early optical counterpart detection
  92. GRB990123 Optical Observation
  93. Possible identification of SN1999E with GRB980910
  94. Optical Observations of GRB 981220
  95. GRB 981226: radio variable
  96. GRB981220
  97. GRB981220, Correction to GCN 179
  98. GRB 981220 Optical observations
  99. GRB 981226 Optical Observations
  100. GRB 981220 and GRB 981226, optical observations

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