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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"

42583 results found.

  1. HETE fluences for GRB021004
  2. GRB 021004, spectroscopic observations
  3. GRB021004: not fading anymore?
  4. GRB 021004: Optical Photometry at 2.5 Days
  5. GRB 021004: polarimetric observations
  6. GRB 021004: V-band Polarimetric Observations
  7. GRB 021004: Optical Decay
  8. GRB021004, astrometric position
  9. GRB021004, Optical Observations
  10. IRAM Millimeter detection of GRB 021004
  11. GRB 021004: Optical observations at RIKEN
  12. GRB 021004 radio observation
  13. GRB 021004: Optical Observations
  14. GRB 021004: Optical Photometry at 1.5 Days
  15. GRB021004, BVRcIc field photometry
  16. GRB 021004: Optical observations
  17. GRB 021004: optical counterpart
  18. GRB 021004, optical observations
  19. GRB021004: Optical Spectroscopy
  20. GRB 021004: Optical Observations
  21. GRB 021004, optical observations
  22. GRB 021004: radio observations
  23. GRB 021004: steepening of the optical decay slope
  24. GRB021004: Upper limits from recent and historical observations
  25. XRF020903, BVRI field photometry
  26. GRB021004: optical observations at Nyrola
  27. GRB021004: Absorption redshift
  28. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  29. GRB021004: optical observations at Bisei
  30. GRB 021004: Kyoto observation
  31. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  32. GRB021004: Optical Afterglow
  33. XRF020903: TNG and Asiago photometry
  34. GRB 020903: Optical observations at RIKEN
  35. XRF 020903: Correction to GCN 1560
  36. XRF 020903: VRI observations
  37. IPN triangulation of GRB020926 (single large error box)
  38. XRF 020903: R band observations
  39. XRF 020903: Archival Optical Images
  40. Radio Observations of XRF 020903: The Missing Link
  41. XRF 020903: Supernova
  42. IPN triangulation of GRB020926 (two large error boxes)
  43. GRB020924 (ecliptic latitude-only localization)
  44. IPN triangulation of GRB020923 (two error boxes)
  45. IPN annulus for GRB020923
  46. IPN triangulation of GRB020914B
  47. Improved IPN position for GRB020918 (two large error boxes)
  48. IPN annulus for GRB020914B
  49. IPN triangulation of GRB020918 (annulus)
  50. IPN triangulation of GRB020911 (2 large error boxes)
  51. IPN triangulation of GRB020914 - clarification and additional information
  52. IPN triangulation of GRB020914
  53. GRB 020305: HST/STIS observations
  54. Confirmation of IPN error box for GRB020910
  55. IPN triangulation of GRB020910
  56. IPN GCN Circulars now to be issued without restriction
  57. Single IPN error box for GRB020904
  58. XRF 020903: optical observation at Kyoto
  59. GRB020322 : HST/STIS observations
  60. XRF 020903: Optical observations
  61. IPN triangulation of GRB020904
  62. XRF 020903: Optical observations
  63. IPN detection of a burst from SGR1900+14
  64. XRF 020903, optical observations
  65. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  66. INTEGRAL GRBs added to GCN
  67. GRB020813: 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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