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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"

23584 results found.

  1. Chandra Observations of SGR 1900+14
  2. Chandra Observations of SGR 1900+14
  3. Possible precursor to the SGR1900+14 giant burst
  4. IPN Triangulation of the Giant Flare from SGR1900+14
  5. GRB010412, field photometry
  6. GRB010412: BeppoSAX GRBM and WFC observations
  7. IPN Triangulation of GRB010412
  8. GRB010412: refined positions from BeppoSAX
  9. GRB Observation Report
  10. REVISED LOCATION OF GRB010326A
  11. GRB 980326: Late-time HST/STIS observations
  12. GRB010324, field photometry
  13. GRB010326B, field photometry
  14. GRB010326, field photometry
  15. GRB010220, field photometry
  16. Further Optical Observations of GRB 010324
  17. GRB010324: BeppoSAX/GRBM data
  18. GRB 010326B: Optical observations
  19. GRB010324, optical observations
  20. GRB010326B: Localization by HETE (2nd GRB for this date)
  21. GRB 010326 optical observations
  22. GRB010326: Refined Localization by HETE
  23. GRB010326: Localization by HETE
  24. Duration, ECT, peak flux and fluence of GRB010324
  25. Optical Observations of GRB 010324
  26. GRB990705, VLT-FORS1 observations of the host galaxy
  27. GRB010222 - Optical observation
  28. GRB010222 - Optical observation
  29. GRB 010222: High-Resolution Keck Spectroscopy
  30. GRB010222: Optical observation and decay
  31. Sub-millimeter Excess/GRB 010222
  32. GRB 010222
  33. GRB 010222 HST/Chandra TOO
  34. GRB010222 further R-band photometry
  35. GRB010222 Optical observations
  36. GRB 010222: Keck Spectroscopy
  37. GRB010214, field photometry
  38. GRB010222, field photometry
  39. GRB010222 further R-band photometry
  40. GRB010222, possible increase of optical decay slope
  41. GRB 010222 Kyoto optical observation
  42. GRB010222: fading behavior
  43. GRB010220, Optical Observations
  44. GRB010222 R-BAND OBSERVATION
  45. GRB010214 follow-up from Hanle
  46. GRB 010222, Decay Slope Confirmed
  47. GRB010222: Another absorption line system
  48. GRB 010214, Optical Observations
  49. GRB010222: R-band fading behavior
  50. GRB010222, optical observations
  51. Redshift of the Optical Transient of GRB010222
  52. GRB010214B,Gamma Ray Observations
  53. GRB010222: possible optical counterpart
  54. GRB010220: BeppoSAX WFC and GRBM preliminary data
  55. GRB010214, optical observations
  56. BeppoSAX ALERT: GRB010220
  57. GRB010214: BeppoSAX WFC and GRBM preliminary data
  58. GRB 010214: X-Ray afterglow
  59. GRB 010214, Optical Observations
  60. GRB 010214 optical observation
  61. GRB010213, Radio Observations
  62. GRB010213 Optical Observation
  63. J-Band Observation of GRB 010214.
  64. GRB010214, optical observations
  65. GRB010213, optical observations
  66. GRB010213, Near-IR observations
  67. Possible InfraRed Transient of GRB 010214.
  68. GRB010214 Optical Observation
  69. GRB010214: BeppoSAX/NFI Observations
  70. GRB010213 (HETE) TAROT observations
  71. GRB010213 detected by HETE
  72. IPN/RXTE TRIANGULATION OF GRB010126
  73. GRB010126, TNG R-band observations
  74. GRB010126 Optical Observations
  75. GRB010126 optical observations
  76. IPN TRIANGULATION OF GRB010126
  77. IPN/RXTE TRIANGULATION OF GRB010126
  78. GRB 010119, optical observations
  79. GRB010119, Radio observations
  80. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  81. IPN TRIANGULATION OF GRB010115
  82. IPN TRIANGULATION OF GRB010109
  83. IPN TRIANGULATION OF GRB010109
  84. IPN triangulation of GRB010104
  85. IPN triangulation of GRB010103
  86. H band observation of GRB 001212
  87. IPN triangulation of GRB001219
  88. GRB 001212 Optical Observation
  89. GRB 001212 Optical Observation
  90. GRB 001212 optical observation
  91. GRB 001212 possible OA in 2MASS
  92. GRB 001212 possible OA
  93. IPN triangulation of GRB001212
  94. GRB001204, Radio observations
  95. IPN triangulation of GRB001204 (short/hard)
  96. GRB 001105, further optical observations
  97. GRB001120: Gunn-i observations
  98. GRB001120, optical observations
  99. IPN triangulation of GRB001120
  100. Optical/NIR observations of GRB001109

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