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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"

43602 results found.

  1. GRB021004, BVRcIc field photometry
  2. GRB 021004: Optical observations
  3. GRB 021004: optical counterpart
  4. GRB 021004, optical observations
  5. GRB021004: Optical Spectroscopy
  6. GRB 021004: Optical Observations
  7. GRB 021004, SPM optical observations
  8. GRB 021004, optical observations
  9. GRB 021004 radio search
  10. GRB 021004: radio observations
  11. GRB 021004: steepening of the optical decay slope
  12. GRB021004: Upper limits from recent and historical observations
  13. XRF020903, BVRI field photometry
  14. GRB021004: optical observations at Nyrola
  15. GRB021004: Absorption redshift
  16. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  17. GRB 021004: Kyoto observation
  18. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  19. GRB021004: Optical Afterglow
  20. XRF020903: TNG and Asiago photometry
  21. GRB 020903: Optical observations at RIKEN
  22. XRF 020903: Correction to GCN 1560
  23. XRF 020903: VRI observations
  24. IPN triangulation of GRB020926 (single large error box)
  25. XRF 020903: R band observations
  26. XRF 020903: Archival Optical Images
  27. Radio Observations of XRF 020903: The Missing Link
  28. XRF 020903: Supernova
  29. IPN triangulation of GRB020926 (two large error boxes)
  30. GRB020924 (ecliptic latitude-only localization)
  31. IPN triangulation of GRB020923 (two error boxes)
  32. IPN annulus for GRB020923
  33. IPN triangulation of GRB020914B
  34. Improved IPN position for GRB020918 (two large error boxes)
  35. IPN annulus for GRB020914B
  36. IPN triangulation of GRB020918 (annulus)
  37. IPN triangulation of GRB020911 (2 large error boxes)
  38. IPN triangulation of GRB020914 - clarification and additional information
  39. IPN triangulation of GRB020914
  40. GRB 020305: HST/STIS observations
  41. Confirmation of IPN error box for GRB020910
  42. IPN triangulation of GRB020910
  43. IPN GCN Circulars now to be issued without restriction
  44. Single IPN error box for GRB020904
  45. XRF 020903: optical observation at Kyoto
  46. GRB020322 : HST/STIS observations
  47. XRF 020903: Optical observations
  48. IPN triangulation of GRB020904
  49. XRF 020903: Optical observations
  50. IPN detection of a burst from SGR1900+14
  51. XRF 020903, optical observations
  52. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  53. INTEGRAL GRBs added to GCN
  54. GRB020813: optical observation
  55. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  56. SGR1900+14 burst localized by HETE
  57. GRB020813: High-resolution optical spectroscopy
  58. GRB020819: optical observations at Bisei
  59. GRB020812: negative optical observations
  60. GRB 020812: optical observation at Kyoto University
  61. Second epoch K band imaging of GRB 020819
  62. GRB020813, Baade 6.5m data now available
  63. GRB 020813 : HST observations
  64. Confirming no variability for GRB02081
  65. GRB020819 : Optical observations at KISO
  66. GRB 020812: early time optical observation at Ouda Station
  67. GRB020813: VRI Decay Slopes
  68. GRB020813: Magellan BVRI Photometry
  69. GRB 020819 : OT candidate - confirmation of non variability
  70. GRB 020819: Optical observations
  71. K band observation of GRB 020819
  72. GRB020819: optical observations
  73. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  74. IPN triangulation of GRB020819 (HETE 2275)
  75. HETE 2275: Optical observations
  76. GRB020813: optical and NIR observations
  77. GRB020813: Fading X-ray Afterglow Observed with Chandra
  78. GRB020813, UBVRI field calibration
  79. GRB 020813: addendum to GCN 1498
  80. GRB020813: optical observations at Bisei
  81. GRB020813: V-band decay slope
  82. GRB020812: NIR observations
  83. Polarimetry of GRB020813: evidence for variability
  84. GRB020813 IRAM millimeter observations
  85. GRB020812: optical observations
  86. GRB020813: High-Resolution Optical Observations
  87. GRB020813(=H2262): Revised Localization with HETE SXC
  88. GRB 020812: optical observation at Bisei
  89. GRB020813: Early Time Magnitude
  90. GRB020813: optical observations; possible host galaxy
  91. GRB 020813, radio detection
  92. GRB 020812 : optical afterglow candidate
  93. GRB020813, optical observations
  94. Millimeter observation of GRB 020813
  95. GRB020812: optical observations
  96. GRB 020813 : KISO multiband optical observations
  97. GRB020813, optical observations
  98. IPN error box for GRB020813
  99. IPN triangulation of GRB020813
  100. GRB020812: possible afterglow candidate

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