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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"

38347 results found.

  1. GRB 021004, spectroscopic observations
  2. GRB021004: not fading anymore?
  3. GRB 021004: Optical Photometry at 2.5 Days
  4. GRB 021004: polarimetric observations
  5. GRB 021004: V-band Polarimetric Observations
  6. GRB 021004: Optical Decay
  7. GRB021004, astrometric position
  8. GRB021004, Optical Observations
  9. GRB 021004: Optical Observations
  10. GRB021004: continued fading
  11. GRB 021004: Optical Photometry at 1.5 Days
  12. GRB021004, Optical Observations
  13. GRB021004, BVRcIc field photometry
  14. GRB 021004: Optical observations
  15. GRB 021004: optical counterpart
  16. GRB 021004, optical observations
  17. GRB021004: Optical Spectroscopy
  18. GRB 021004: Optical Observations
  19. GRB 021004, SPM optical observations
  20. GRB 021004: radio observations
  21. GRB 021004: steepening of the optical decay slope
  22. GRB021004: Upper limits from recent and historical observations
  23. XRF020903, BVRI field photometry
  24. GRB021004: optical observations at Nyrola
  25. GRB021004: Absorption redshift
  26. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  27. GRB 021004: Kyoto observation
  28. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  29. GRB021004: Optical Afterglow
  30. XRF020903: TNG and Asiago photometry
  31. XRF 020903: Correction to GCN 1560
  32. XRF 020903: VRI observations
  33. IPN triangulation of GRB020926 (single large error box)
  34. GRB 020903: correction to GCN 1557
  35. XRF 020903: R band observations
  36. XRF 020903: Archival Optical Images
  37. Radio Observations of XRF 020903: The Missing Link
  38. XRF 020903: Supernova
  39. IPN triangulation of GRB020926 (two large error boxes)
  40. GRB020924 (ecliptic latitude-only localization)
  41. IPN triangulation of GRB020923 (two error boxes)
  42. IPN annulus for GRB020923
  43. IPN triangulation of GRB020914B
  44. Improved IPN position for GRB020918 (two large error boxes)
  45. IPN annulus for GRB020914B
  46. IPN triangulation of GRB020918 (annulus)
  47. IPN triangulation of GRB020911 (2 large error boxes)
  48. IPN triangulation of GRB020914 - clarification and additional information
  49. IPN triangulation of GRB020914
  50. GRB 020305: HST/STIS observations
  51. Confirmation of IPN error box for GRB020910
  52. IPN triangulation of GRB020910
  53. IPN GCN Circulars now to be issued without restriction
  54. Single IPN error box for GRB020904
  55. XRF 020903: optical observation at Kyoto
  56. GRB020322 : HST/STIS observations
  57. XRF 020903: Optical observations
  58. IPN triangulation of GRB020904
  59. XRF 020903: Optical observations
  60. IPN detection of a burst from SGR1900+14
  61. XRF 020903, optical observations
  62. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  63. GRB020813: optical observation
  64. GRB020812: optical observation
  65. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  66. SGR1900+14 burst localized by HETE
  67. GRB020813: High-resolution optical spectroscopy
  68. GRB020812: negative optical observations
  69. GRB 020812: optical observation at Kyoto University
  70. Second epoch K band imaging of GRB 020819
  71. GRB020813, Baade 6.5m data now available
  72. GRB 020813 : HST observations
  73. Confirming no variability for GRB02081
  74. GRB020819 : Optical observations at KISO
  75. GRB 020812: early time optical observation at Ouda Station
  76. GRB020813: VRI Decay Slopes
  77. GRB020813: Magellan BVRI Photometry
  78. GRB 020819 : OT candidate - confirmation of non variability
  79. K band observation of GRB 020819
  80. GRB020819: optical observations
  81. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  82. IPN triangulation of GRB020819 (HETE 2275)
  83. GRB020813: optical and NIR observations
  84. GRB020813: Fading X-ray Afterglow Observed with Chandra
  85. GRB020813, UBVRI field calibration
  86. GRB 020813: addendum to GCN 1498
  87. GRB020813: V-band decay slope
  88. GRB020812: NIR observations
  89. GRB020813 IRAM millimeter observations
  90. GRB020813: High-Resolution Optical Observations
  91. GRB020813(=H2262): Revised Localization with HETE SXC
  92. GRB020813: Early Time Magnitude
  93. GRB020813: optical observations; possible host galaxy
  94. GRB 020813, radio detection
  95. GRB 020812 : optical afterglow candidate
  96. GRB020813, optical observations
  97. Millimeter observation of GRB 020813
  98. GRB020812: optical observations
  99. GRB020813, optical observations
  100. IPN error box for GRB020813

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