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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"

17798 results found.

  1. SGR1900+14: A Burst Localized by HETE
  2. SGR1806-20: A Second, Intense Burst Localized by HETE
  3. SGR1806-20: Localization by HETE
  4. HETE Fully-Automated GCN Notices
  5. GRB000301C: Late-time HST/STIS observation
  6. GRB010518: a faint BeppoSAX detection
  7. GRB000418: HST/STIS Second-epoch Observations
  8. X-ray precursors to the large flare from SGR 1900+14
  9. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  10. Millimeter observation of SGR 1900+14
  11. Chandra Observations of SGR 1900+14
  12. SGR1900+14, I-band observations
  13. GRB010412, field photometry
  14. Giant flare from SGR1900+14
  15. GRB 010326b Optical Observations
  16. GRB010412: BeppoSAX GRBM and WFC observations
  17. IPN Triangulation of GRB010412
  18. GRB010324, revised field photometry
  19. GRB 980326: Late-time HST/STIS observations
  20. GRB010324, field photometry
  21. GRB010326B, field photometry
  22. GRB010326, field photometry
  23. GRB010220, field photometry
  24. Further Optical Observations of GRB 010324
  25. GRB010222, CXO X-ray observations
  26. GRB010324, optical observations
  27. GRB010326B: Localization by HETE (2nd GRB for this date)
  28. GRB 010326 optical observations
  29. GRB010326: Refined Localization by HETE
  30. GRB010326: Localization by HETE
  31. Optical Observations of GRB 010324
  32. GRB010222, late-time optical observation
  33. Support extension to the BeppoSAX mission
  34. GRB 010222, Optical Observations
  35. GRB 010222: High-Resolution Keck Spectroscopy
  36. GRB 010222 HST/Chandra TOO
  37. GRB010222 further R-band photometry
  38. GRB 010222: Keck Spectroscopy
  39. GRB010214, field photometry
  40. GRB010222, field photometry
  41. GRB010222 further R-band photometry
  42. GRB 010222 Kyoto optical observation
  43. GRB010222 R-BAND OBSERVATION
  44. GRB010214 follow-up from Hanle
  45. GRB 010222: Near-IR Observations
  46. GRB 010222: Optical Observations
  47. GRB010222, radio observations
  48. GRB010222, optical observations
  49. GRB010222: BeppoSAX/NFI Observations
  50. GRB 010220, simultaneous optical observations
  51. GRB010220: BeppoSAX WFC and GRBM preliminary data
  52. GRB010214, optical observations
  53. GRB010214: BeppoSAX WFC and GRBM preliminary data
  54. GRB 010214: X-Ray afterglow
  55. GRB 010214 optical observation
  56. J-Band Observation of GRB 010214.
  57. GRB010213, Near-IR observations
  58. Possible InfraRed Transient of GRB 010214.
  59. GRB010213 detected by HETE
  60. IPN Status Report
  61. HETE Status
  62. Optical Observations of GRB 001018 at Keck
  63. Optical observations of GRB 001018 with JCAM
  64. GRB 001212 Optical Observation
  65. GRB 001212 Optical Observation
  66. GRB001120, optical observations
  67. Optical/NIR observations of GRB001109
  68. GRB 001109: deep JHK upper limits
  69. GRB 001109 X-ray afterglow with BeppoSAX
  70. CORRECTION to XMM-Newton observation of GRB001025
  71. GRB001109: Optical observations
  72. GRB001109, Radio observations
  73. GRB001105 BVRI field photometry correction
  74. GRB001105, BVRI field photometry
  75. GRB 001025B, Optical obervations
  76. GRB 991208: HST Imaging of the Host Galaxy
  77. GRB 001025B, I-band observations
  78. GRB001007: Optical observations
  79. GRB001007, Radio observations
  80. IPN TRIANGULATION OF GRB 001017
  81. V,R,I band observations of GRB000926
  82. GRB000926 - Amateur Optical Observations
  83. CONCAM null result on GRB001005
  84. HETE-2 Launches Successfully
  85. HETE-2 48 hour Launch Delay
  86. GRB000926 - Optical observations
  87. GRB000926 - Optical observations
  88. GRB 000926, Optical Observations
  89. GRB000926 K'-band Observation
  90. J and K band observations of GRB 000926
  91. GRB 000926, optical observation by Oksanen (vsnet-grb)
  92. CONCAM crude optical limits before and after GRB000926
  93. GRB 000926 HST/Chandra TOO Status
  94. GRB 000926: Optical candidate
  95. Optical candidate for GRB000926
  96. GRB 000911, BVRI field photometry
  97. GRB000911, Radio and Optical observations
  98. GRB000911: Optical observations
  99. IPN triangulation of GRB000911
  100. GRB000830, BVRI field photometry

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