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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"

32492 results found.

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

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