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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"

18330 results found.

  1. XRF011030: Chandra Observations
  2. GRB011030: Z-band observations
  3. Non-triggered burst 011030 ("GRB 011030")
  4. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  5. GRB 970828: HST Observations of the Host Galaxy
  6. GRB 000131: HST Detection of the Host Galaxy
  7. GRB 970828: HST Observations of the Host Galaxy
  8. GRB010921, optical observation
  9. GRB011019: Subaru Optical Observations
  10. GRB011030 - further refinement WFC position
  11. GRB011030: radio search
  12. GRB 010921: Possible supernova component
  13. GRB010921, optical observation at early time
  14. GRB 010921, I-band observations
  15. GRB011019, optical observations
  16. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  17. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  18. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  19. GRB010928(=H1770): Localization of a Long GRB by HETE
  20. GRB010921, negative optical observations
  21. GRB010921 field photometry
  22. GRB000926, Host Galaxy Observations
  23. GRB001109, Host Galaxy Spectroscopic Observations
  24. Probable SGR or Short Duration GRB Detected by HETE
  25. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  26. GRB 010222 - WHT BVRI images
  27. GRB 010629 Optical Observations
  28. SGR1900+14: High Fluence Burst Localized by HETE
  29. GRB010629, optical observations
  30. IPN triangulation of GRB010629
  31. GRB010629: A Burst Localized by HETE
  32. SGR1900+14: Second Burst Localized by HETE
  33. SGR1900+14: A Burst Localized by HETE
  34. SGR1806-20: A Second, Intense Burst Localized by HETE
  35. SGR1806-20: Localization by HETE
  36. HETE Fully-Automated GCN Notices
  37. GRB000301C: Late-time HST/STIS observation
  38. GRB010518: a faint BeppoSAX detection
  39. GRB000418: HST/STIS Second-epoch Observations
  40. X-ray precursors to the large flare from SGR 1900+14
  41. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  42. Millimeter observation of SGR 1900+14
  43. Chandra Observations of SGR 1900+14
  44. SGR1900+14, I-band observations
  45. GRB010412, field photometry
  46. Giant flare from SGR1900+14
  47. GRB 010326b Optical Observations
  48. GRB010412: BeppoSAX GRBM and WFC observations
  49. IPN Triangulation of GRB010412
  50. GRB010324, revised field photometry
  51. GRB 980326: Late-time HST/STIS observations
  52. GRB010324, field photometry
  53. GRB010326B, field photometry
  54. GRB010326, field photometry
  55. GRB010220, field photometry
  56. Further Optical Observations of GRB 010324
  57. GRB010222, CXO X-ray observations
  58. GRB010324, optical observations
  59. GRB010326B: Localization by HETE (2nd GRB for this date)
  60. GRB 010326 optical observations
  61. GRB010326: Refined Localization by HETE
  62. GRB010326: Localization by HETE
  63. Optical Observations of GRB 010324
  64. GRB010222, late-time optical observation
  65. Support extension to the BeppoSAX mission
  66. GRB 010222, Optical Observations
  67. GRB 010222: High-Resolution Keck Spectroscopy
  68. GRB 010222 HST/Chandra TOO
  69. GRB010222 further R-band photometry
  70. GRB 010222: Keck Spectroscopy
  71. GRB010214, field photometry
  72. GRB010222, field photometry
  73. GRB010222 further R-band photometry
  74. GRB 010222 Kyoto optical observation
  75. GRB010222 R-BAND OBSERVATION
  76. GRB010214 follow-up from Hanle
  77. GRB 010222: Near-IR Observations
  78. GRB 010222: Optical Observations
  79. GRB010222, radio observations
  80. GRB010222, optical observations
  81. GRB010222: BeppoSAX/NFI Observations
  82. GRB 010220, simultaneous optical observations
  83. GRB010220: BeppoSAX WFC and GRBM preliminary data
  84. GRB010214, optical observations
  85. GRB010214: BeppoSAX WFC and GRBM preliminary data
  86. GRB 010214: X-Ray afterglow
  87. GRB 010214 optical observation
  88. J-Band Observation of GRB 010214.
  89. GRB010213, Near-IR observations
  90. Possible InfraRed Transient of GRB 010214.
  91. GRB010213 detected by HETE
  92. IPN Status Report
  93. HETE Status
  94. Optical Observations of GRB 001018 at Keck
  95. Optical observations of GRB 001018 with JCAM
  96. GRB 001212 Optical Observation
  97. GRB 001212 Optical Observation
  98. GRB001120, optical observations
  99. Optical/NIR observations of GRB001109
  100. GRB 001109: deep JHK upper limits

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