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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"

25012 results found.

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

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