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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"

44990 results found.

  1. GRB 021004: Optical Decay
  2. GRB021004, astrometric position
  3. GRB021004, Optical Observations
  4. IRAM Millimeter detection of GRB 021004
  5. GRB 021004: Optical observations at RIKEN
  6. GRB 021004 radio observation
  7. GRB 021004: Optical Observations
  8. GRB021004: continued fading
  9. GRB 021004: Optical Photometry at 1.5 Days
  10. GRB021004, Optical Observations
  11. GRB021004, BVRcIc field photometry
  12. GRB 021004: Optical observations
  13. GRB 021004: optical counterpart
  14. GRB 021004, optical observations
  15. GRB021004: Optical Spectroscopy
  16. GRB 021004: Optical Observations
  17. GRB 021004, SPM optical observations
  18. GRB 021004, optical observations
  19. GRB 021004 radio search
  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. GRB021004: optical observations at Bisei
  28. GRB 021004: Kyoto observation
  29. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  30. GRB021004: Optical Afterglow
  31. XRF020903: TNG and Asiago photometry
  32. GRB 020903: Optical observations at RIKEN
  33. XRF 020903: Correction to GCN 1560
  34. XRF 020903: VRI observations
  35. IPN triangulation of GRB020926 (single large error box)
  36. GRB 020903: correction to GCN 1557
  37. XRF 020903: R band observations
  38. XRF 020903: Archival Optical Images
  39. Radio Observations of XRF 020903: The Missing Link
  40. XRF 020903: Supernova
  41. IPN triangulation of GRB020926 (two large error boxes)
  42. GRB020924 (ecliptic latitude-only localization)
  43. IPN triangulation of GRB020923 (two error boxes)
  44. IPN annulus for GRB020923
  45. IPN triangulation of GRB020914B
  46. Improved IPN position for GRB020918 (two large error boxes)
  47. IPN annulus for GRB020914B
  48. IPN triangulation of GRB020918 (annulus)
  49. IPN triangulation of GRB020911 (2 large error boxes)
  50. IPN triangulation of GRB020914 - clarification and additional information
  51. IPN triangulation of GRB020914
  52. GRB 020305: HST/STIS observations
  53. Confirmation of IPN error box for GRB020910
  54. IPN triangulation of GRB020910
  55. IPN GCN Circulars now to be issued without restriction
  56. Single IPN error box for GRB020904
  57. XRF 020903: optical observation at Kyoto
  58. GRB020322 : HST/STIS observations
  59. XRF 020903: Optical observations
  60. IPN triangulation of GRB020904
  61. XRF 020903: Optical observations
  62. IPN detection of a burst from SGR1900+14
  63. XRF 020903, optical observations
  64. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  65. INTEGRAL GRBs added to GCN
  66. GRB020813: optical observation
  67. GRB020812: optical observation
  68. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  69. SGR1900+14 burst localized by HETE
  70. GRB020813: High-resolution optical spectroscopy
  71. GRB020819: optical observations at Bisei
  72. GRB020812: negative optical observations
  73. GRB 020812: optical observation at Kyoto University
  74. Second epoch K band imaging of GRB 020819
  75. GRB020813, Baade 6.5m data now available
  76. GRB 020813 : HST observations
  77. Confirming no variability for GRB02081
  78. GRB020819 : Optical observations at KISO
  79. GRB 020812: early time optical observation at Ouda Station
  80. GRB020813: VRI Decay Slopes
  81. GRB020813: Magellan BVRI Photometry
  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. IPN triangulation of GRB020819 (HETE 2275)
  88. HETE 2275: Optical observations
  89. GRB020813: optical and NIR observations
  90. GRB020813: Fading X-ray Afterglow Observed with Chandra
  91. GRB020813, UBVRI field calibration
  92. GRB 020813: addendum to GCN 1498
  93. GRB020813: optical observations at Bisei
  94. GRB020813: V-band decay slope
  95. GRB020812: NIR observations
  96. Polarimetry of GRB020813: evidence for variability
  97. GRB020813 IRAM millimeter observations
  98. GRB020812: optical observations
  99. GRB020813: High-Resolution Optical Observations
  100. GRB020813(=H2262): Revised Localization with HETE SXC

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