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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"

32494 results found.

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

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