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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"

32495 results found.

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

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