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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"

32489 results found.

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

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