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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"

24595 results found.

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

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