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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"

18334 results found.

  1. GRB 011121: Detection of Bright IR Counterpart
  2. GRB011121: possible redshift, continued decay
  3. GRB 011030: TNG K-band observation
  4. XRF011030: J and K band observations
  5. XRF011030: Chandra Observations
  6. GRB011030: Z-band observations
  7. Non-triggered burst 011030 ("GRB 011030")
  8. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  9. GRB 970828: HST Observations of the Host Galaxy
  10. GRB 000131: HST Detection of the Host Galaxy
  11. GRB 970828: HST Observations of the Host Galaxy
  12. GRB010921, optical observation
  13. GRB011019: Subaru Optical Observations
  14. GRB011030 - further refinement WFC position
  15. GRB011030: radio search
  16. GRB 010921: Possible supernova component
  17. GRB010921, optical observation at early time
  18. GRB 010921, I-band observations
  19. GRB011019, optical observations
  20. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  21. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  22. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  23. GRB010928(=H1770): Localization of a Long GRB by HETE
  24. GRB010921, negative optical observations
  25. GRB010921 field photometry
  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. GRB 010222 - WHT BVRI images
  31. GRB 010629 Optical Observations
  32. SGR1900+14: High Fluence Burst Localized by HETE
  33. GRB010629, optical observations
  34. IPN triangulation of GRB010629
  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. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  46. Millimeter observation of SGR 1900+14
  47. Chandra Observations 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. IPN Triangulation of GRB010412
  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, 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. GRB010222, late-time optical observation
  69. Support extension to the BeppoSAX mission
  70. GRB 010222, Optical Observations
  71. GRB 010222: High-Resolution Keck Spectroscopy
  72. GRB 010222 HST/Chandra TOO
  73. GRB010222 further R-band photometry
  74. GRB 010222: Keck Spectroscopy
  75. GRB010214, field photometry
  76. GRB010222, field photometry
  77. GRB010222 further R-band photometry
  78. GRB 010222 Kyoto optical observation
  79. GRB010222 R-BAND OBSERVATION
  80. GRB010214 follow-up from Hanle
  81. GRB 010222: Near-IR Observations
  82. GRB 010222: Optical Observations
  83. GRB010222, radio observations
  84. GRB010222, optical observations
  85. GRB010222: BeppoSAX/NFI Observations
  86. GRB 010220, simultaneous optical observations
  87. GRB010220: BeppoSAX WFC and GRBM preliminary data
  88. GRB010214, optical observations
  89. GRB010214: BeppoSAX WFC and GRBM preliminary data
  90. GRB 010214: X-Ray afterglow
  91. GRB 010214 optical observation
  92. J-Band Observation of GRB 010214.
  93. GRB010213, Near-IR observations
  94. Possible InfraRed Transient of GRB 010214.
  95. GRB010213 detected by HETE
  96. IPN Status Report
  97. HETE Status
  98. Optical Observations of GRB 001018 at Keck
  99. Optical observations of GRB 001018 with JCAM
  100. GRB 001212 Optical Observation

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