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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"

18100 results found.

  1. GRB020124(=H1896): Localization of a Long GRB by HETE
  2. Possible optical counterpart to a GRB
  3. GRB011212, Optical Observations
  4. GRB011211: BeppoSAX/GRBM data
  5. Optical polarization observations for GRB011211
  6. GRB 011130: Optical Observations of X-ray and Radio Sources
  7. GRB 011212: optical observation at Asiago
  8. GRB 011211: Evidence for an Optical Break
  9. GRB 011212: optical observation at Oslo (relayed)
  10. GRB 011211: Optical Spectroscopy
  11. GRB 011211, Optical Observations
  12. GRB011212, BVRI field photometry
  13. GRB011211, BVRI field photometry
  14. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  15. Fading of the optical source associated of XRF 011211
  16. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  17. GRB011130 (XRF011130) Chandra Observations
  18. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  19. GRB 011130, K band observations
  20. GRB011130 (XRF011130) SDSS PT i-band observations
  21. XRF011130: Infrared Observations
  22. GRB 011121: J-band observations
  23. GRB 011121: NIR observations, host galaxy?
  24. GRB011121: UBRI Observations
  25. GRB 011121 J-Band Astrometry
  26. GRB 011121: Detection of Bright IR Counterpart
  27. GRB011121: possible redshift, continued decay
  28. GRB 011030: TNG K-band observation
  29. XRF011030: J and K band observations
  30. GRB011030, optical observation
  31. XRF011030: Chandra Observations
  32. GRB011030: Z-band observations
  33. GRB 011030 I-band Observation
  34. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  35. GRB 970828: HST Observations of the Host Galaxy
  36. GRB 000131: HST Detection of the Host Galaxy
  37. GRB 970828: HST Observations of the Host Galaxy
  38. GRB011019: Subaru Optical Observations
  39. GRB011030 - further refinement WFC position
  40. GRB011030: radio search
  41. GRB 010921: Possible supernova component
  42. GRB010921, optical observation at early time
  43. GRB 010921, I-band observations
  44. GRB011019, optical observations
  45. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  46. GRB010921: Spectroscopy of the Host Galaxy
  47. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  48. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  49. GRB010928(=H1770): Localization of a Long GRB by HETE
  50. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  51. GRB010921, negative optical observations
  52. GRB010921 field photometry
  53. H1761: A Bright GRB Detected by HETE
  54. GRB000926, Host Galaxy Observations
  55. GRB001109, Host Galaxy Spectroscopic Observations
  56. Probable SGR or Short Duration GRB Detected by HETE
  57. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  58. BeppoSAX/GRBM detection of GRB010728
  59. GRB 010222 - WHT BVRI images
  60. GRB 010629 Optical Observations
  61. SGR1900+14: High Fluence Burst Localized by HETE
  62. GRB010629, optical observations
  63. GRB010629: A Burst Localized by HETE
  64. SGR1900+14: Second Burst Localized by HETE
  65. SGR1900+14: A Burst Localized by HETE
  66. SGR1806-20: A Second, Intense Burst Localized by HETE
  67. SGR1806-20: Localization by HETE
  68. HETE Fully-Automated GCN Notices
  69. GRB000301C: Late-time HST/STIS observation
  70. GRB010518: a faint BeppoSAX detection
  71. GRB000418: HST/STIS Second-epoch Observations
  72. X-ray precursors to the large flare from SGR 1900+14
  73. GRB010427, Gamma Ray Observations
  74. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  75. Millimeter observation of SGR 1900+14
  76. SGR1900+14, I-band observations
  77. GRB010412, field photometry
  78. Giant flare from SGR1900+14
  79. GRB 010326b Optical Observations
  80. GRB010412: BeppoSAX GRBM and WFC observations
  81. GRB010324, revised field photometry
  82. GRB 980326: Late-time HST/STIS observations
  83. GRB010324, field photometry
  84. GRB010326B, field photometry
  85. GRB010326, field photometry
  86. GRB010220, field photometry
  87. Further Optical Observations of GRB 010324
  88. GRB010222, CXO X-ray observations
  89. GRB010324: BeppoSAX/GRBM data
  90. GRB010324, optical observations
  91. GRB010326B: Localization by HETE (2nd GRB for this date)
  92. GRB 010326 optical observations
  93. GRB010326: Refined Localization by HETE
  94. GRB010326: Localization by HETE
  95. Optical Observations of GRB 010324
  96. IPN TRIANGULATION OF GRB010324
  97. GRB010222, late-time optical observation
  98. Support extension to the BeppoSAX mission
  99. GRB 010222, Optical Observations
  100. GRB010220 optical obsercations

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