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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"
  1. XRF 020903: Supernova
  2. IPN triangulation of GRB020926 (two large error boxes)
  3. GRB020924 (ecliptic latitude-only localization)
  4. IPN triangulation of GRB020923 (two error boxes)
  5. IPN annulus for GRB020923
  6. IPN triangulation of GRB020914B
  7. Improved IPN position for GRB020918 (two large error boxes)
  8. IPN annulus for GRB020914B
  9. IPN triangulation of GRB020918 (annulus)
  10. IPN triangulation of GRB020911 (2 large error boxes)
  11. IPN triangulation of GRB020914 - clarification and additional information
  12. IPN triangulation of GRB020914
  13. GRB 020305: HST/STIS observations
  14. Confirmation of IPN error box for GRB020910
  15. IPN triangulation of GRB020910
  16. IPN GCN Circulars now to be issued without restriction
  17. Single IPN error box for GRB020904
  18. XRF 020903: optical observation at Kyoto
  19. GRB020322 : HST/STIS observations
  20. XRF 020903: Optical observations
  21. IPN triangulation of GRB020904
  22. XRF 020903: Optical observations
  23. IPN detection of a burst from SGR1900+14
  24. XRF 020903, optical observations
  25. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  26. INTEGRAL GRBs added to GCN
  27. GRB020813: optical observation
  28. GRB020812: optical observation
  29. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  30. SGR1900+14 burst localized by HETE
  31. GRB020813: High-resolution optical spectroscopy
  32. GRB020819: optical observations at Bisei
  33. GRB020812: negative optical observations
  34. GRB 020812: optical observation at Kyoto University
  35. Second epoch K band imaging of GRB 020819
  36. GRB020813, Baade 6.5m data now available
  37. GRB 020813 : HST observations
  38. Confirming no variability for GRB02081
  39. GRB020819 : Optical observations at KISO
  40. GRB 020812: early time optical observation at Ouda Station
  41. GRB020813: VRI Decay Slopes
  42. GRB020813: Magellan BVRI Photometry
  43. GRB 020819 : OT candidate - confirmation of non variability
  44. GRB 020819: Optical observations
  45. K band observation of GRB 020819
  46. GRB020819: optical observations
  47. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  48. IPN triangulation of GRB020819 (HETE 2275)
  49. HETE 2275: Optical observations
  50. GRB020813: optical and NIR observations
  51. GRB020813: Fading X-ray Afterglow Observed with Chandra
  52. GRB020813, UBVRI field calibration
  53. GRB 020813: addendum to GCN 1498
  54. GRB020813: optical observations at Bisei
  55. GRB020813: V-band decay slope
  56. GRB020812: NIR observations
  57. Polarimetry of GRB020813: evidence for variability
  58. GRB020813 IRAM millimeter observations
  59. GRB020812: optical observations
  60. GRB020813: High-Resolution Optical Observations
  61. GRB020813(=H2262): Revised Localization with HETE SXC
  62. GRB 020812: optical observation at Bisei
  63. GRB020813: Early Time Magnitude
  64. GRB020813: optical observations; possible host galaxy
  65. GRB 020813, radio detection
  66. GRB 020812 : optical afterglow candidate
  67. GRB020813, optical observations
  68. Millimeter observation of GRB 020813
  69. GRB020812: optical observations
  70. GRB 020813 : KISO multiband optical observations
  71. GRB020813, optical observations
  72. IPN error box for GRB020813
  73. IPN triangulation of GRB020813
  74. GRB020812: possible afterglow candidate
  75. Early Time Limits for GRB020813
  76. GRB020812: possible afterglow candidate
  77. GRB020813, astrometric position
  78. Spectropolarimetry of GRB 020813
  79. GRB 020813 Afterglow Observations; Possible break
  80. GRB 020813: Absorption redshift
  81. GRB 020813 multiband optical observations
  82. GRB020813: optical afterglow
  83. GRB020813: Fading of Candidate OT
  84. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  85. GRB020813: Candidate Optical Afterglow
  86. GRB 020812 optical observation
  87. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  88. GRB 020715, optical observations
  89. GRB 020714, optical observations
  90. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  91. GRB020801: Candidate OT present in DSS
  92. HST Imaging of the Host of GRB 011121
  93. GRB020801, optical afterglow candidate
  94. Further refinement to IPN error box for GRB020531
  95. GRB020331: Late-time Optical Light Curve (re-submission)
  96. GRB020331: Late-time Optical Light Curve
  97. GRB 020405: HST observations reveal red bump
  98. IPN triangulation of GRB020714
  99. IPN triangulation of GRB020715 (=GRB150702)
  100. IPN triangulation of GRB020714

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