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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"

43604 results found.

  1. GRB 021004: Optical Photometry at 1.5 Days
  2. GRB021004, Optical Observations
  3. GRB021004, BVRcIc field photometry
  4. GRB 021004: Optical observations
  5. GRB 021004: optical counterpart
  6. GRB 021004, optical observations
  7. GRB021004: Optical Spectroscopy
  8. GRB 021004: Optical Observations
  9. GRB 021004, SPM optical observations
  10. GRB 021004, optical observations
  11. GRB 021004 radio search
  12. GRB 021004: radio observations
  13. GRB 021004: steepening of the optical decay slope
  14. GRB021004: Upper limits from recent and historical observations
  15. XRF020903, BVRI field photometry
  16. GRB021004: optical observations at Nyrola
  17. GRB021004: Absorption redshift
  18. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  19. GRB 021004: Kyoto observation
  20. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  21. GRB021004: Optical Afterglow
  22. XRF020903: TNG and Asiago photometry
  23. GRB 020903: Optical observations at RIKEN
  24. XRF 020903: Correction to GCN 1560
  25. XRF 020903: VRI observations
  26. IPN triangulation of GRB020926 (single large error box)
  27. XRF 020903: R band observations
  28. XRF 020903: Archival Optical Images
  29. Radio Observations of XRF 020903: The Missing Link
  30. XRF 020903: Supernova
  31. IPN triangulation of GRB020926 (two large error boxes)
  32. GRB020924 (ecliptic latitude-only localization)
  33. IPN triangulation of GRB020923 (two error boxes)
  34. IPN annulus for GRB020923
  35. IPN triangulation of GRB020914B
  36. Improved IPN position for GRB020918 (two large error boxes)
  37. IPN annulus for GRB020914B
  38. IPN triangulation of GRB020918 (annulus)
  39. IPN triangulation of GRB020911 (2 large error boxes)
  40. IPN triangulation of GRB020914 - clarification and additional information
  41. IPN triangulation of GRB020914
  42. GRB 020305: HST/STIS observations
  43. Confirmation of IPN error box for GRB020910
  44. IPN triangulation of GRB020910
  45. IPN GCN Circulars now to be issued without restriction
  46. Single IPN error box for GRB020904
  47. XRF 020903: optical observation at Kyoto
  48. GRB020322 : HST/STIS observations
  49. XRF 020903: Optical observations
  50. IPN triangulation of GRB020904
  51. XRF 020903: Optical observations
  52. IPN detection of a burst from SGR1900+14
  53. XRF 020903, optical observations
  54. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  55. INTEGRAL GRBs added to GCN
  56. GRB020813: optical observation
  57. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  58. SGR1900+14 burst localized by HETE
  59. GRB020813: High-resolution optical spectroscopy
  60. GRB020819: optical observations at Bisei
  61. GRB020812: negative optical observations
  62. GRB 020812: optical observation at Kyoto University
  63. Second epoch K band imaging of GRB 020819
  64. GRB020813, Baade 6.5m data now available
  65. GRB 020813 : HST observations
  66. Confirming no variability for GRB02081
  67. GRB020819 : Optical observations at KISO
  68. GRB 020812: early time optical observation at Ouda Station
  69. GRB020813: VRI Decay Slopes
  70. GRB020813: Magellan BVRI Photometry
  71. GRB 020819 : OT candidate - confirmation of non variability
  72. GRB 020819: Optical observations
  73. K band observation of GRB 020819
  74. GRB020819: optical observations
  75. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  76. IPN triangulation of GRB020819 (HETE 2275)
  77. HETE 2275: Optical observations
  78. GRB020813: optical and NIR observations
  79. GRB020813: Fading X-ray Afterglow Observed with Chandra
  80. GRB020813, UBVRI field calibration
  81. GRB 020813: addendum to GCN 1498
  82. GRB020813: optical observations at Bisei
  83. GRB020813: V-band decay slope
  84. GRB020812: NIR observations
  85. Polarimetry of GRB020813: evidence for variability
  86. GRB020813 IRAM millimeter observations
  87. GRB020812: optical observations
  88. GRB020813: High-Resolution Optical Observations
  89. GRB020813(=H2262): Revised Localization with HETE SXC
  90. GRB 020812: optical observation at Bisei
  91. GRB020813: Early Time Magnitude
  92. GRB020813: optical observations; possible host galaxy
  93. GRB 020813, radio detection
  94. GRB 020812 : optical afterglow candidate
  95. GRB020813, optical observations
  96. Millimeter observation of GRB 020813
  97. GRB020812: optical observations
  98. GRB 020813 : KISO multiband optical observations
  99. GRB020813, optical observations
  100. IPN error box for GRB020813

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