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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"

45491 results found.

  1. GRB 021004: optical spectroscopy
  2. IPN triangulation of GRB021007 (annulus)
  3. XRF 020903 spectrum
  4. GRB 021004: HST/STIS spectroscopic observations
  5. GRB021004: optical observations and predicted break time
  6. GRB021004: BVRc photometry
  7. GRB 021004 redshift
  8. GRB021004 radio observation
  9. GRB021004: restart of optical decay
  10. GRB 021004: Optical Decay
  11. GRB 021004 continued IR fading
  12. HETE fluences for GRB021004
  13. GRB 021004, spectroscopic observations
  14. GRB021004: not fading anymore?
  15. GRB 021004: Optical Photometry at 2.5 Days
  16. GRB 021004: polarimetric observations
  17. GRB 021004: V-band Polarimetric Observations
  18. GRB021004: Update Bisei photometric data
  19. GRB 021004: Optical Decay
  20. GRB021004, astrometric position
  21. GRB021004, Optical Observations
  22. IRAM Millimeter detection of GRB 021004
  23. GRB 021004: Optical observations at RIKEN
  24. GRB 021004 radio observation
  25. GRB 021004: Optical Observations
  26. GRB021004: continued fading
  27. GRB 021004: Optical Photometry at 1.5 Days
  28. GRB021004, Optical Observations
  29. GRB021004, BVRcIc field photometry
  30. GRB 021004: Optical observations
  31. GRB 021004: optical counterpart
  32. GRB 021004, optical observations
  33. GRB021004: Optical Spectroscopy
  34. GRB 021004: Optical Observations
  35. GRB 021004, SPM optical observations
  36. GRB 021004, optical observations
  37. GRB 021004 radio search
  38. GRB 021004: radio observations
  39. GRB 021004: steepening of the optical decay slope
  40. GRB021004: Upper limits from recent and historical observations
  41. XRF020903, BVRI field photometry
  42. GRB021004: optical observations at Nyrola
  43. GRB021004: Absorption redshift
  44. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  45. GRB021004: optical observations at Bisei
  46. GRB 021004: Kyoto observation
  47. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  48. GRB021004: Optical Afterglow
  49. XRF020903: TNG and Asiago photometry
  50. GRB 020903: Optical observations at RIKEN
  51. XRF 020903: Correction to GCN 1560
  52. XRF 020903: VRI observations
  53. IPN triangulation of GRB020926 (single large error box)
  54. GRB 020903: correction to GCN 1557
  55. XRF 020903: R band observations
  56. XRF 020903: Archival Optical Images
  57. Radio Observations of XRF 020903: The Missing Link
  58. XRF 020903: Supernova
  59. IPN triangulation of GRB020926 (two large error boxes)
  60. GRB020924 (ecliptic latitude-only localization)
  61. IPN triangulation of GRB020923 (two error boxes)
  62. IPN annulus for GRB020923
  63. IPN triangulation of GRB020914B
  64. Improved IPN position for GRB020918 (two large error boxes)
  65. IPN annulus for GRB020914B
  66. IPN triangulation of GRB020918 (annulus)
  67. IPN triangulation of GRB020911 (2 large error boxes)
  68. IPN triangulation of GRB020914 - clarification and additional information
  69. IPN triangulation of GRB020914
  70. GRB 020305: HST/STIS observations
  71. Confirmation of IPN error box for GRB020910
  72. IPN triangulation of GRB020910
  73. IPN GCN Circulars now to be issued without restriction
  74. Single IPN error box for GRB020904
  75. XRF 020903: optical observation at Kyoto
  76. GRB020322 : HST/STIS observations
  77. XRF 020903: Optical observations
  78. IPN triangulation of GRB020904
  79. XRF 020903: Optical observations
  80. IPN detection of a burst from SGR1900+14
  81. XRF 020903, optical observations
  82. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  83. INTEGRAL GRBs added to GCN
  84. GRB020813: optical observation
  85. GRB020812: optical observation
  86. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  87. SGR1900+14 burst localized by HETE
  88. GRB020813: High-resolution optical spectroscopy
  89. GRB020819: optical observations at Bisei
  90. GRB020812: negative optical observations
  91. GRB 020812: optical observation at Kyoto University
  92. Second epoch K band imaging of GRB 020819
  93. GRB020813, Baade 6.5m data now available
  94. GRB 020813 : HST observations
  95. Confirming no variability for GRB02081
  96. GRB020819 : Optical observations at KISO
  97. GRB 020812: early time optical observation at Ouda Station
  98. GRB020813: VRI Decay Slopes
  99. GRB020813: Magellan BVRI Photometry
  100. GRB 020819 : OT candidate - confirmation of non variability

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