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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"

19041 results found.

  1. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  2. IPN error box for GRB990527
  3. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  4. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  5. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  6. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  7. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  8. radio observations of X-ray/GRB transient field
  9. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  10. Optical report on X-ray/GRB transient
  11. radio detection of X-ray/GRB transient
  12. GRB 990510: optical linear polarization
  13. GRB 990510: optical observations
  14. GRB990510: X-ray afterglow
  15. GRB 990510 optical observations
  16. GRB990510: NFI X-ray source
  17. GRB 990506 Radio Observations
  18. GRB 990123, optical monitoring
  19. GRB 990506, optical observations
  20. GRB 990510: Final BeppoSAX-WFC Coordinates
  21. GRB 990506, Optical Observations
  22. GRB 990506 optical observations
  23. GRB 990506 optical observations
  24. GRB 990506, optical observations
  25. GRB990506 observation plan
  26. GRB 990506, optical observations from +1 to +3 hours
  27. GRB 990506, optical observations
  28. GRB990506 observation plan
  29. GRB 990316 Optical Observations
  30. GRB 990316 optical observations
  31. GRB990316: simultaneous optical observation
  32. GRB990308, Possible new SGR~0209+70
  33. GRB 990123, Field Photometry
  34. GRB 990217 Optical Observations
  35. BATSE Flight Anomaly
  36. GRB990217: BeppoSAX/GRBM data
  37. GRB990123 observations
  38. GRB990123, Optical Observation
  39. GRB 990123: Discovery of the Probable Host Galaxy
  40. GRB19990123 observations
  41. GRB 990123: BVRI standards in the field
  42. GRB981220, field photometry
  43. GRB990123, Optical observation
  44. GRB 990123: Publicly available reduced HST images
  45. GRB990123, Upcoming HST Service Observations
  46. GRB990123, 15-GHz limits
  47. GRB 990123: New Constraints on Possible Foreground Galaxies
  48. GRB990123 Optical Observations
  49. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  50. GRB 990123: Continued Radio Observations
  51. GRB990123, Preliminary Lens Search Results
  52. Search for Potential Images of GRB 990123
  53. GRB990123, Optical BVRI Observations
  54. GRB 990123: near-infrared observations.
  55. GRB990123, OSSE observations
  56. GRB990123: NIR Observation
  57. "GRB 990123: New BV Observations"
  58. GRB 990123: New Optical Observations, Decay Measure
  59. GRB 990123 Optical Follow-Up
  60. GRB 990123: Possible Gravitationally Lensed Burst?
  61. GRB990123, optical observation
  62. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  63. GRB 990123 r-band photometry
  64. GRB 990123 Optical Follow-up
  65. Optical Observations of GRB 981220
  66. GRB 981226: radio variable
  67. GRB 981226 Optical Observations
  68. GRB981226 BeppoSAX follow up
  69. GRB 981226
  70. GRB 981226 optical observations
  71. GRB 981220:Optical Observations
  72. GRB981226, BeppoSAX Christmas GRB
  73. GRB 981226 optical observations
  74. GRB 981220, radio observations
  75. GRB 981220
  76. GRB 980326/Host Galaxy
  77. BeppoSAX NFI Observation of GRB980425
  78. GRB980329 R,I flux calibration and R,I,K upper limits
  79. GRB980425 Optical Follow-up
  80. GRB970508 optical observations
  81. GRB980519, Optical Observations
  82. GRB 980703 (NFI observations)
  83. GRB980703 optical photometry
  84. GRB980703 optical observations
  85. GRB980703: Radio transient
  86. GRB980703 Transient Optical Follow-Up
  87. GRB980703: LOTIS observation at early times
  88. BeppoSAX NFI observations of GRB 980703
  89. GRB980703 optical followup
  90. SGR1627-41
  91. Radio observations of SGRs
  92. SGR1900+14 field optical observations
  93. GRB 980613 Near-IR observations
  94. GRB 980613: Optical transient and its host galaxy
  95. SGR1627-41, Refined IPN annulus location
  96. GRB 980613: Detection of the probable host galaxy
  97. SGR 1627-41
  98. GRB 980613 Optical Observations
  99. GRB 980613 optical observations
  100. Discovery of a new SGR source, SGR1627-41

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