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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"

19572 results found.

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

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