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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"

42205 results found.

  1. GRB 021004: steepening of the optical decay slope
  2. GRB021004: Upper limits from recent and historical observations
  3. XRF020903, BVRI field photometry
  4. GRB021004: optical observations at Nyrola
  5. GRB021004: Absorption redshift
  6. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  7. GRB021004: optical observations at Bisei
  8. GRB 021004: Kyoto observation
  9. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  10. GRB021004: Optical Afterglow
  11. XRF020903: TNG and Asiago photometry
  12. GRB 020903: Optical observations at RIKEN
  13. XRF 020903: Correction to GCN 1560
  14. XRF 020903: VRI observations
  15. IPN triangulation of GRB020926 (single large error box)
  16. XRF 020903: R band observations
  17. XRF 020903: Archival Optical Images
  18. Radio Observations of XRF 020903: The Missing Link
  19. XRF 020903: Supernova
  20. IPN triangulation of GRB020926 (two large error boxes)
  21. GRB020924 (ecliptic latitude-only localization)
  22. IPN annulus for GRB020923
  23. IPN triangulation of GRB020914B
  24. Improved IPN position for GRB020918 (two large error boxes)
  25. IPN annulus for GRB020914B
  26. IPN triangulation of GRB020911 (2 large error boxes)
  27. IPN triangulation of GRB020914 - clarification and additional information
  28. IPN triangulation of GRB020914
  29. GRB 020305: HST/STIS observations
  30. IPN GCN Circulars now to be issued without restriction
  31. XRF 020903: optical observation at Kyoto
  32. GRB020322 : HST/STIS observations
  33. XRF 020903: Optical observations
  34. IPN triangulation of GRB020904
  35. XRF 020903: Optical observations
  36. IPN detection of a burst from SGR1900+14
  37. XRF 020903, optical observations
  38. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  39. INTEGRAL GRBs added to GCN
  40. GRB020813: optical observation
  41. GRB020812: optical observation
  42. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  43. SGR1900+14 burst localized by HETE
  44. GRB020813: High-resolution optical spectroscopy
  45. GRB020819: optical observations at Bisei
  46. GRB020812: negative optical observations
  47. GRB 020812: optical observation at Kyoto University
  48. Second epoch K band imaging of GRB 020819
  49. GRB020813, Baade 6.5m data now available
  50. GRB 020813 : HST observations
  51. Confirming no variability for GRB02081
  52. GRB020819 : Optical observations at KISO
  53. GRB 020812: early time optical observation at Ouda Station
  54. GRB020813: VRI Decay Slopes
  55. GRB020813: Magellan BVRI Photometry
  56. GRB 020819 : OT candidate - confirmation of non variability
  57. GRB 020819: Optical observations
  58. K band observation of GRB 020819
  59. GRB020819: optical observations
  60. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  61. IPN triangulation of GRB020819 (HETE 2275)
  62. HETE 2275: Optical observations
  63. GRB020813: optical and NIR observations
  64. GRB020813: Fading X-ray Afterglow Observed with Chandra
  65. GRB020813, UBVRI field calibration
  66. GRB 020813: addendum to GCN 1498
  67. GRB020813: optical observations at Bisei
  68. GRB020813: V-band decay slope
  69. GRB020812: NIR observations
  70. Polarimetry of GRB020813: evidence for variability
  71. GRB020813 IRAM millimeter observations
  72. GRB020812: optical observations
  73. GRB020813: High-Resolution Optical Observations
  74. GRB020813(=H2262): Revised Localization with HETE SXC
  75. GRB 020812: optical observation at Bisei
  76. GRB020813: Early Time Magnitude
  77. GRB020813: optical observations; possible host galaxy
  78. GRB 020813, radio detection
  79. GRB 020812 : optical afterglow candidate
  80. GRB020813, optical observations
  81. Millimeter observation of GRB 020813
  82. GRB020812: optical observations
  83. GRB 020813 : KISO multiband optical observations
  84. GRB020813, optical observations
  85. IPN error box for GRB020813
  86. IPN triangulation of GRB020813
  87. GRB020812: possible afterglow candidate
  88. Early Time Limits for GRB020813
  89. GRB020812: possible afterglow candidate
  90. GRB020813, astrometric position
  91. Spectropolarimetry of GRB 020813
  92. GRB 020813: Absorption redshift
  93. GRB 020813 multiband optical observations
  94. GRB020813: optical afterglow
  95. GRB020813: Fading of Candidate OT
  96. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  97. GRB020813: Candidate Optical Afterglow
  98. GRB 020812 optical observation
  99. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  100. GRB 020715, optical observations

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