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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"

27886 results found.

  1. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  2. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  3. radio observations of X-ray/GRB transient field
  4. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  5. Optical report on X-ray/GRB transient
  6. radio detection of X-ray/GRB transient
  7. BeppoSAX: A new fast X-ray transient
  8. GRB 990510: optical observations
  9. GRB 990510: optical linear polarization
  10. GRB 990510: optical observations
  11. GRB990510: X-ray afterglow
  12. GRB 990510: Broad Band Break
  13. GRB 990510: BATSE Observations
  14. GRB 990510: BeppoSAX/GRBM observations
  15. GRB990510 optical observations
  16. GRB 990510 optical observations
  17. GRB 990506 Radio Observations
  18. GRB 990123, optical monitoring
  19. GRB 990506: BATSE Observations
  20. GRB 990506, optical observations
  21. GRB 990506, Optical Observations
  22. GRB 990506 optical observations
  23. GRB 990506, optical observations
  24. GRB 990506, armchair astronomy
  25. GRB 990506, optical observations from +1 to +3 hours
  26. GRB 990506, optical observations
  27. GRB990506 observation plan
  28. IPN localization for GRB990506
  29. GRB990323 PRECISE IPN POSITION
  30. GRB 990316 Optical Observations
  31. GRB 990316 optical observations
  32. GRB990316: simultaneous optical observation
  33. GRB990316 - Optical null results
  34. GRB990308 not a new SGR
  35. GRB 990308a and GRB 990308b
  36. GRB990308, Possible new SGR~0209+70
  37. GRB 990123, Field Photometry
  38. GRB 990217 Optical Observations
  39. BATSE Flight Anomaly
  40. GRB990217: BeppoSAX/GRBM data
  41. GRB990123 observations
  42. GRB990217 Optical observation
  43. GRB990123, Optical Observation
  44. GRB 990123: Discovery of the Probable Host Galaxy
  45. GRB 990123: Reduced HST Images
  46. GRB19990123 observations
  47. GRB 990123: BVRI standards in the field
  48. GRB981220, field photometry
  49. GRB990123, Optical observation
  50. GRB990123, 15-GHz limits
  51. GRB 990123: New Constraints on Possible Foreground Galaxies
  52. GRB990123 Optical Observations
  53. GRB990123, Probability of gravitational lensing
  54. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  55. GRB990123, Preliminary Lens Search Results
  56. On the Lensing Interpretation of GRB 990123
  57. Search for Potential Images of GRB 990123
  58. Search for Potential Images of GRB 990123
  59. GRB990123, Optical BVRI Observations
  60. GRB 990123: near-infrared observations.
  61. GRB990123, OSSE observations
  62. GRB990123: NIR Observation
  63. GRB990123, ASCA X-ray observation of afterglow
  64. "GRB 990123: New BV Observations"
  65. GRB 990123 Optical Follow-Up
  66. GRB 990123: BATSE Observations
  67. GRB990123 Optical Observations
  68. GRB 990123: New Optical Observations, Decay Measure
  69. GRB 990123 Optical Follow-Up
  70. GRB 990123: Possible Gravitationally Lensed Burst?
  71. GRB990123, optical observation
  72. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  73. GRB990123, Optical observation
  74. GRB 990123: Optical Decay Slope
  75. GRB 990123 r-band photometry
  76. GRB 990123 Optical Follow-up
  77. GRB990123, early optical counterpart detection
  78. GRB990123 Optical Observation
  79. Possible identification of SN1999E with GRB980910
  80. Optical Observations of GRB 981220
  81. GRB 981226: radio variable
  82. GRB981220
  83. GRB981220, Correction to GCN 179
  84. GRB 981220 Optical observations
  85. GRB 981226 Optical Observations
  86. GRB 981220 and GRB 981226, optical observations
  87. GRB981226 Optical Observations
  88. GRB981226 BeppoSAX follow up
  89. GRB 981226
  90. GRB 981226 optical observations
  91. GRB981220 B, R and I band observations
  92. Optical Observations of GRB981226
  93. GRB 981220:Optical Observations
  94. GRB 981226 optical observations
  95. GRB 981220
  96. GRB 981220, radio observations
  97. GRB981220 I-band Observations
  98. GRB 981220
  99. GRB 980326/Host Galaxy
  100. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results

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