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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"

18055 results found.

  1. GRB 990705, R-band observations
  2. GRB990704: SAX-NFI results summary
  3. GRB990704 radio and optical observations
  4. GRB990704
  5. GRB990704, optical observations
  6. GRB990704: possible X-ray afterglow
  7. GRB990704
  8. GRB990704: BeppoSAX detection
  9. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  10. GRB 990627, radio observations
  11. Late-time HST/STIS Observation of GRB 990123
  12. Optical Observations of GRB 990506
  13. GRB 990506 Radio Transient
  14. GRB990527 Optical Observations
  15. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  16. IPN error box for GRB990527
  17. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  18. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  19. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  20. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  21. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  22. radio observations of X-ray/GRB transient field
  23. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  24. Optical report on X-ray/GRB transient
  25. radio detection of X-ray/GRB transient
  26. GRB 990510: optical linear polarization
  27. GRB 990510: optical observations
  28. GRB990510: X-ray afterglow
  29. GRB 990510 optical observations
  30. GRB990510: NFI X-ray source
  31. GRB 990506 Radio Observations
  32. GRB 990123, optical monitoring
  33. GRB 990506, optical observations
  34. GRB 990510: Final BeppoSAX-WFC Coordinates
  35. GRB 990506, Optical Observations
  36. GRB 990506 optical observations
  37. GRB 990506 optical observations
  38. GRB 990506, optical observations
  39. GRB990506 observation plan
  40. GRB 990506, optical observations from +1 to +3 hours
  41. GRB 990506, optical observations
  42. GRB990506 observation plan
  43. GRB 990316 Optical Observations
  44. GRB 990316 optical observations
  45. GRB990316: simultaneous optical observation
  46. GRB990308, Possible new SGR~0209+70
  47. GRB 990123, Field Photometry
  48. GRB 990217 Optical Observations
  49. BATSE Flight Anomaly
  50. GRB990217: BeppoSAX/GRBM data
  51. GRB990123 observations
  52. GRB990123, Optical Observation
  53. GRB 990123: Discovery of the Probable Host Galaxy
  54. GRB19990123 observations
  55. GRB 990123: BVRI standards in the field
  56. GRB981220, field photometry
  57. GRB990123, Optical observation
  58. GRB 990123: Publicly available reduced HST images
  59. GRB990123, Upcoming HST Service Observations
  60. GRB990123, 15-GHz limits
  61. GRB 990123: New Constraints on Possible Foreground Galaxies
  62. GRB990123 Optical Observations
  63. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  64. GRB 990123: Continued Radio Observations
  65. GRB990123, Preliminary Lens Search Results
  66. Search for Potential Images of GRB 990123
  67. GRB990123, Optical BVRI Observations
  68. GRB 990123: near-infrared observations.
  69. GRB990123, OSSE observations
  70. GRB990123: NIR Observation
  71. "GRB 990123: New BV Observations"
  72. GRB 990123: New Optical Observations, Decay Measure
  73. GRB 990123 Optical Follow-Up
  74. GRB 990123: Possible Gravitationally Lensed Burst?
  75. GRB990123, optical observation
  76. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  77. GRB 990123 r-band photometry
  78. GRB 990123 Optical Follow-up
  79. Optical Observations of GRB 981220
  80. GRB 981226: radio variable
  81. GRB 981226 Optical Observations
  82. GRB981226 BeppoSAX follow up
  83. GRB 981226
  84. GRB 981226 optical observations
  85. GRB 981220:Optical Observations
  86. GRB981226, BeppoSAX Christmas GRB
  87. GRB 981226 optical observations
  88. GRB 981220, radio observations
  89. GRB 981220
  90. GRB 980326/Host Galaxy
  91. BeppoSAX NFI Observation of GRB980425
  92. GRB980329 R,I flux calibration and R,I,K upper limits
  93. GRB980425 Optical Follow-up
  94. GRB970508 optical observations
  95. GRB980519, Optical Observations
  96. GRB 980703 (NFI observations)
  97. GRB980703 optical photometry
  98. GRB980703 optical observations
  99. GRB980703: Radio transient
  100. GRB980703 Transient Optical Follow-Up

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