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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"

17373 results found.

  1. GRB 011030: TNG K-band observation
  2. XRF011030: J and K band observations
  3. GRB011030, optical observation
  4. XRF011030: Chandra Observations
  5. GRB011030: Z-band observations
  6. GRB 011030 I-band Observation
  7. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  8. GRB 970828: HST Observations of the Host Galaxy
  9. GRB 000131: HST Detection of the Host Galaxy
  10. GRB 970828: HST Observations of the Host Galaxy
  11. GRB011019: Subaru Optical Observations
  12. GRB011030 - further refinement WFC position
  13. GRB011030: radio search
  14. GRB 010921: Possible supernova component
  15. GRB010921, optical observation at early time
  16. GRB 010921, I-band observations
  17. GRB011019, optical observations
  18. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  19. GRB010921: Spectroscopy of the Host Galaxy
  20. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  21. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  22. GRB010928(=H1770): Localization of a Long GRB by HETE
  23. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  24. GRB010921, negative optical observations
  25. GRB010921 field photometry
  26. H1761: A Bright GRB Detected by HETE
  27. GRB000926, Host Galaxy Observations
  28. GRB001109, Host Galaxy Spectroscopic Observations
  29. Probable SGR or Short Duration GRB Detected by HETE
  30. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  31. BeppoSAX/GRBM detection of GRB010728
  32. GRB 010222 - WHT BVRI images
  33. GRB 010629 Optical Observations
  34. SGR1900+14: High Fluence Burst Localized by HETE
  35. GRB010629, optical observations
  36. GRB010629: A Burst Localized by HETE
  37. SGR1900+14: Second Burst Localized by HETE
  38. SGR1900+14: A Burst Localized by HETE
  39. SGR1806-20: A Second, Intense Burst Localized by HETE
  40. SGR1806-20: Localization by HETE
  41. HETE Fully-Automated GCN Notices
  42. GRB000301C: Late-time HST/STIS observation
  43. GRB010518: a faint BeppoSAX detection
  44. GRB000418: HST/STIS Second-epoch Observations
  45. X-ray precursors to the large flare from SGR 1900+14
  46. GRB010427, Gamma Ray Observations
  47. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  48. Millimeter observation of SGR 1900+14
  49. SGR1900+14, I-band observations
  50. GRB010412, field photometry
  51. Giant flare from SGR1900+14
  52. GRB 010326b Optical Observations
  53. GRB010412: BeppoSAX GRBM and WFC observations
  54. GRB010324, revised field photometry
  55. GRB 980326: Late-time HST/STIS observations
  56. GRB010324, field photometry
  57. GRB010326B, field photometry
  58. GRB010326, field photometry
  59. GRB010220, field photometry
  60. Further Optical Observations of GRB 010324
  61. GRB010222, CXO X-ray observations
  62. GRB010324: BeppoSAX/GRBM data
  63. GRB010324, optical observations
  64. GRB010326B: Localization by HETE (2nd GRB for this date)
  65. GRB 010326 optical observations
  66. GRB010326: Refined Localization by HETE
  67. GRB010326: Localization by HETE
  68. Optical Observations of GRB 010324
  69. IPN TRIANGULATION OF GRB010324
  70. GRB010222, late-time optical observation
  71. Support extension to the BeppoSAX mission
  72. GRB 010222, Optical Observations
  73. GRB010220 optical obsercations
  74. GRB010222 - Optical observation
  75. GRB010222 further R-band photometry
  76. GRB 010222: Keck Spectroscopy
  77. GRB010214, field photometry
  78. GRB010222, field photometry
  79. GRB010222 further R-band photometry
  80. GRB 010222 Kyoto optical observation
  81. GRB010222 R-BAND OBSERVATION
  82. GRB010214 follow-up from Hanle
  83. GRB 010222: Near-IR Observations
  84. GRB 010222: Optical Observations
  85. GRB 010222, Decay Slope Confirmed
  86. GRB010222, radio observations
  87. GRB010222, optical observations
  88. GRB 010220, simultaneous optical observations
  89. GRB010220: BeppoSAX WFC and GRBM preliminary data
  90. GRB010214, optical observations
  91. GRB010214: BeppoSAX WFC and GRBM preliminary data
  92. GRB 010214: X-Ray afterglow
  93. GRB 010214 optical observation
  94. J-Band Observation of GRB 010214.
  95. GRB010214, optical observations
  96. GRB010213, optical observations
  97. GRB010213, Near-IR observations
  98. Possible InfraRed Transient of GRB 010214.
  99. GRB010214 Optical Observation
  100. GRB010213 detected by HETE

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