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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"

27323 results found.

  1. GRB 991014, Optical Observations
  2. GRB 991014, optical observations
  3. GRB 990915 optical observations
  4. Optical Observations of GRB990907
  5. GRB990907: BeppoSAX follow up and X-ray afterglow
  6. GRB990907 and 990908
  7. GRB 990712 Late Optical Decay and Host Galaxy
  8. GRB990806 BeppoSAX follow up
  9. GRB990806: BATSE Observations
  10. GRB 990806 Optical observations
  11. GRB 990806, Optical Observations
  12. GRB 990806, optical observations
  13. GRB 990806, Optical Observations
  14. GRB990806 UBVRIJHK observations
  15. GRB 990712 Optical Observations
  16. GRB 990712
  17. Late-time HST/STIS Observations of GRB 990510
  18. BeppoSAX NFI Observation of GRB990705
  19. BeppoSAX NFI Observation of GRB990705
  20. GRB 990705, R-band observations
  21. Infrared and Optical Observations of GRB990705
  22. GRB990704: SAX-NFI results summary
  23. GRB990704 radio and optical observations
  24. GRB990704
  25. GRB990704, optical observations
  26. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  27. Optical Observations of GRB990627
  28. BeppoSAX: GRB990625
  29. Late-time HST/STIS Observation of GRB 990123
  30. Optical Observations of GRB 990506
  31. GRB990527 Optical Observations
  32. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  33. Late Afterglows of GRBs 990510, 990123
  34. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  35. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  36. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  37. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  38. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  39. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  40. radio observations of X-ray/GRB transient field
  41. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  42. Optical report on X-ray/GRB transient
  43. radio detection of X-ray/GRB transient
  44. BeppoSAX: A new fast X-ray transient
  45. GRB 990510: optical observations
  46. GRB 990510: optical linear polarization
  47. GRB 990510: optical observations
  48. GRB990510: X-ray afterglow
  49. GRB 990510: Broad Band Break
  50. GRB 990510: BATSE Observations
  51. GRB 990510: BeppoSAX/GRBM observations
  52. GRB990510 optical observations
  53. GRB 990510 optical observations
  54. GRB 990506 Radio Observations
  55. GRB 990123, optical monitoring
  56. GRB 990506: BATSE Observations
  57. GRB 990506, optical observations
  58. GRB 990506, Optical Observations
  59. GRB 990506 optical observations
  60. GRB 990506, optical observations
  61. GRB 990506, armchair astronomy
  62. GRB 990506, optical observations from +1 to +3 hours
  63. GRB 990506, optical observations
  64. GRB990506 observation plan
  65. IPN localization for GRB990506
  66. GRB990323 PRECISE IPN POSITION
  67. GRB 990316 Optical Observations
  68. GRB 990316 optical observations
  69. GRB990316: simultaneous optical observation
  70. GRB990316 - Optical null results
  71. GRB990308 not a new SGR
  72. GRB 990308a and GRB 990308b
  73. GRB990308, Possible new SGR~0209+70
  74. GRB 990123, Field Photometry
  75. GRB 990217 Optical Observations
  76. BATSE Flight Anomaly
  77. GRB990217: BeppoSAX/GRBM data
  78. GRB990123 observations
  79. GRB990217 Optical observation
  80. GRB990123, Optical Observation
  81. GRB 990123: Discovery of the Probable Host Galaxy
  82. GRB 990123: Reduced HST Images
  83. GRB19990123 observations
  84. GRB 990123: BVRI standards in the field
  85. GRB981220, field photometry
  86. GRB990123, Optical observation
  87. GRB990123, 15-GHz limits
  88. GRB 990123: New Constraints on Possible Foreground Galaxies
  89. GRB990123 Optical Observations
  90. GRB990123, Probability of gravitational lensing
  91. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  92. GRB990123, Preliminary Lens Search Results
  93. On the Lensing Interpretation of GRB 990123
  94. Search for Potential Images of GRB 990123
  95. Search for Potential Images of GRB 990123
  96. GRB990123, Optical BVRI Observations
  97. GRB 990123: near-infrared observations.
  98. GRB990123, OSSE observations
  99. GRB990123: NIR Observation
  100. GRB990123, ASCA X-ray observation of afterglow

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