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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"

23576 results found.

  1. GRB Observation Report
  2. REVISED LOCATION OF GRB010326A
  3. GRB 980326: Late-time HST/STIS observations
  4. GRB010324, field photometry
  5. GRB010326B, field photometry
  6. GRB010326, field photometry
  7. GRB010220, field photometry
  8. Further Optical Observations of GRB 010324
  9. GRB010324: BeppoSAX/GRBM data
  10. GRB 010326B: Optical observations
  11. GRB010324, optical observations
  12. GRB010326B: Localization by HETE (2nd GRB for this date)
  13. GRB 010326 optical observations
  14. GRB010326: Refined Localization by HETE
  15. GRB010326: Localization by HETE
  16. Duration, ECT, peak flux and fluence of GRB010324
  17. Optical Observations of GRB 010324
  18. GRB990705, VLT-FORS1 observations of the host galaxy
  19. GRB010222 - Optical observation
  20. GRB010222 - Optical observation
  21. GRB 010222: High-Resolution Keck Spectroscopy
  22. GRB010222: Optical observation and decay
  23. Sub-millimeter Excess/GRB 010222
  24. GRB 010222
  25. GRB 010222 HST/Chandra TOO
  26. GRB010222 further R-band photometry
  27. GRB010222 Optical observations
  28. GRB 010222: Keck Spectroscopy
  29. GRB010214, field photometry
  30. GRB010222, field photometry
  31. GRB010222 further R-band photometry
  32. GRB010222, possible increase of optical decay slope
  33. GRB 010222 Kyoto optical observation
  34. GRB010222: fading behavior
  35. GRB010220, Optical Observations
  36. GRB010222 R-BAND OBSERVATION
  37. GRB010214 follow-up from Hanle
  38. GRB 010222, Decay Slope Confirmed
  39. GRB010222: Another absorption line system
  40. GRB 010214, Optical Observations
  41. GRB010222: R-band fading behavior
  42. GRB010222, optical observations
  43. Redshift of the Optical Transient of GRB010222
  44. GRB010214B,Gamma Ray Observations
  45. GRB010222: possible optical counterpart
  46. GRB010220: BeppoSAX WFC and GRBM preliminary data
  47. GRB010214, optical observations
  48. BeppoSAX ALERT: GRB010220
  49. GRB010214: BeppoSAX WFC and GRBM preliminary data
  50. GRB 010214: X-Ray afterglow
  51. GRB 010214, Optical Observations
  52. GRB 010214 optical observation
  53. GRB010213, Radio Observations
  54. GRB010213 Optical Observation
  55. J-Band Observation of GRB 010214.
  56. GRB010214, optical observations
  57. GRB010213, optical observations
  58. GRB010213, Near-IR observations
  59. Possible InfraRed Transient of GRB 010214.
  60. GRB010214 Optical Observation
  61. GRB010214: BeppoSAX/NFI Observations
  62. GRB010213 (HETE) TAROT observations
  63. GRB010213 detected by HETE
  64. IPN/RXTE TRIANGULATION OF GRB010126
  65. GRB010126, TNG R-band observations
  66. GRB010126 Optical Observations
  67. GRB010126 optical observations
  68. IPN TRIANGULATION OF GRB010126
  69. IPN/RXTE TRIANGULATION OF GRB010126
  70. GRB 010119, optical observations
  71. GRB010119, Radio observations
  72. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  73. IPN TRIANGULATION OF GRB010115
  74. IPN TRIANGULATION OF GRB010109
  75. IPN TRIANGULATION OF GRB010109
  76. IPN triangulation of GRB010104
  77. IPN triangulation of GRB010103
  78. H band observation of GRB 001212
  79. IPN triangulation of GRB001219
  80. GRB 001212 Optical Observation
  81. GRB 001212 Optical Observation
  82. GRB 001212 optical observation
  83. GRB 001212 possible OA in 2MASS
  84. GRB 001212 possible OA
  85. IPN triangulation of GRB001212
  86. GRB001204, Radio observations
  87. IPN triangulation of GRB001204 (short/hard)
  88. GRB 001105, further optical observations
  89. GRB001120: Gunn-i observations
  90. GRB001120, optical observations
  91. IPN triangulation of GRB001120
  92. Optical/NIR observations of GRB001109
  93. GRB 001109: deep JHK upper limits
  94. GRB 001109 X-ray afterglow with BeppoSAX
  95. GRB001109: Optical observations
  96. GRB001105, BVRI field photometry
  97. GRB 001105, R-band observation
  98. IPN TRIANGULATION OF GRB001105
  99. GRB 001025B, Optical obervations
  100. GRB000926: R-image of the host galaxy

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