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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"

44412 results found.

  1. IPN triangulation of GRB021013 (annulus)
  2. XRF 020903: flattening of the optical light curve.
  3. GRB021004, UBVRcIc field photometry update
  4. IPN triangulation of GRB021008 (single error box)
  5. GRB021004: Optical Observations
  6. GRB 021004 submm observations
  7. IPN triangulation of GRB021008B (annulus)
  8. IPN triangulation of GRB021008 (two small error boxes)
  9. GRB021004 Chandra HETG Observations
  10. GRB 021004: Optical/NIR Observations
  11. GRB 021004: Additional V-band Polarimetric Observations
  12. GRB021004: optical observation
  13. GRB 021004: Host Galaxy Star Formation Rate
  14. GRB 021004 submm observations
  15. GRB 021004: WC wind?
  16. IPN triangulation of GRB021008
  17. GRB021004: NIR and Optical observations
  18. GRB 021004: Optical measurement at OHP
  19. GRB 021004: Optical observations, AUDE network
  20. GRB 021004 - VLA Radio Observations
  21. GRB 021004 - Unusual Radio-to-Submm Spectrum
  22. GRB 021004: optical spectroscopy
  23. IPN triangulation of GRB021007 (annulus)
  24. XRF 020903 spectrum
  25. GRB 021004: HST/STIS spectroscopic observations
  26. GRB021004: optical observations and predicted break time
  27. GRB021004: BVRc photometry
  28. GRB 021004 redshift
  29. GRB021004 radio observation
  30. GRB021004: restart of optical decay
  31. GRB 021004: Optical Decay
  32. GRB 021004 continued IR fading
  33. HETE fluences for GRB021004
  34. GRB 021004, spectroscopic observations
  35. GRB021004: not fading anymore?
  36. GRB 021004: Optical Photometry at 2.5 Days
  37. GRB 021004: polarimetric observations
  38. GRB 021004: V-band Polarimetric Observations
  39. GRB021004: Update Bisei photometric data
  40. GRB 021004: Optical Decay
  41. GRB021004, astrometric position
  42. GRB021004, Optical Observations
  43. IRAM Millimeter detection of GRB 021004
  44. GRB 021004: Optical observations at RIKEN
  45. GRB 021004 radio observation
  46. GRB 021004: Optical Observations
  47. GRB021004: continued fading
  48. GRB 021004: Optical Photometry at 1.5 Days
  49. GRB021004, Optical Observations
  50. GRB021004, BVRcIc field photometry
  51. GRB 021004: Optical observations
  52. GRB 021004: optical counterpart
  53. GRB 021004, optical observations
  54. GRB021004: Optical Spectroscopy
  55. GRB 021004: Optical Observations
  56. GRB 021004, SPM optical observations
  57. GRB 021004, optical observations
  58. GRB 021004 radio search
  59. GRB 021004: radio observations
  60. GRB 021004: steepening of the optical decay slope
  61. GRB021004: Upper limits from recent and historical observations
  62. XRF020903, BVRI field photometry
  63. GRB021004: optical observations at Nyrola
  64. GRB021004: Absorption redshift
  65. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  66. GRB021004: optical observations at Bisei
  67. GRB 021004: Kyoto observation
  68. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  69. GRB021004: Optical Afterglow
  70. XRF020903: TNG and Asiago photometry
  71. GRB 020903: Optical observations at RIKEN
  72. XRF 020903: Correction to GCN 1560
  73. XRF 020903: VRI observations
  74. IPN triangulation of GRB020926 (single large error box)
  75. GRB 020903: correction to GCN 1557
  76. XRF 020903: R band observations
  77. XRF 020903: Archival Optical Images
  78. Radio Observations of XRF 020903: The Missing Link
  79. XRF 020903: Supernova
  80. IPN triangulation of GRB020926 (two large error boxes)
  81. GRB020924 (ecliptic latitude-only localization)
  82. IPN triangulation of GRB020923 (two error boxes)
  83. IPN annulus for GRB020923
  84. IPN triangulation of GRB020914B
  85. Improved IPN position for GRB020918 (two large error boxes)
  86. IPN annulus for GRB020914B
  87. IPN triangulation of GRB020918 (annulus)
  88. IPN triangulation of GRB020911 (2 large error boxes)
  89. IPN triangulation of GRB020914 - clarification and additional information
  90. IPN triangulation of GRB020914
  91. GRB 020305: HST/STIS observations
  92. Confirmation of IPN error box for GRB020910
  93. IPN triangulation of GRB020910
  94. IPN GCN Circulars now to be issued without restriction
  95. Single IPN error box for GRB020904
  96. XRF 020903: optical observation at Kyoto
  97. GRB020322 : HST/STIS observations
  98. XRF 020903: Optical observations
  99. IPN triangulation of GRB020904
  100. XRF 020903: Optical observations

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