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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"

38358 results found.

  1. GRB 021004 - Unusual Radio-to-Submm Spectrum
  2. GRB 021004: optical spectroscopy
  3. IPN triangulation of GRB021007 (annulus)
  4. XRF 020903 spectrum
  5. GRB 021004: HST/STIS spectroscopic observations
  6. GRB021004: optical observations and predicted break time
  7. GRB 021004 redshift
  8. GRB021004: restart of optical decay
  9. GRB 021004: Optical Decay
  10. GRB 021004 continued IR fading
  11. HETE fluences for GRB021004
  12. GRB 021004, spectroscopic observations
  13. GRB021004: not fading anymore?
  14. GRB 021004: Optical Photometry at 2.5 Days
  15. GRB 021004: polarimetric observations
  16. GRB 021004: V-band Polarimetric Observations
  17. GRB 021004: Optical Decay
  18. GRB021004, astrometric position
  19. GRB021004, Optical Observations
  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: radio observations
  32. GRB 021004: steepening of the optical decay slope
  33. GRB021004: Upper limits from recent and historical observations
  34. XRF020903, BVRI field photometry
  35. GRB021004: optical observations at Nyrola
  36. GRB021004: Absorption redshift
  37. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  38. GRB 021004: Kyoto observation
  39. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  40. GRB021004: Optical Afterglow
  41. XRF020903: TNG and Asiago photometry
  42. XRF 020903: Correction to GCN 1560
  43. XRF 020903: VRI observations
  44. IPN triangulation of GRB020926 (single large error box)
  45. GRB 020903: correction to GCN 1557
  46. XRF 020903: R band observations
  47. XRF 020903: Archival Optical Images
  48. Radio Observations of XRF 020903: The Missing Link
  49. XRF 020903: Supernova
  50. IPN triangulation of GRB020926 (two large error boxes)
  51. GRB020924 (ecliptic latitude-only localization)
  52. IPN triangulation of GRB020923 (two error boxes)
  53. IPN annulus for GRB020923
  54. IPN triangulation of GRB020914B
  55. Improved IPN position for GRB020918 (two large error boxes)
  56. IPN annulus for GRB020914B
  57. IPN triangulation of GRB020918 (annulus)
  58. IPN triangulation of GRB020911 (2 large error boxes)
  59. IPN triangulation of GRB020914 - clarification and additional information
  60. IPN triangulation of GRB020914
  61. GRB 020305: HST/STIS observations
  62. Confirmation of IPN error box for GRB020910
  63. IPN triangulation of 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. IPN detection of a burst from SGR1900+14
  72. XRF 020903, optical observations
  73. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  74. GRB020813: optical observation
  75. GRB020812: optical observation
  76. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  77. SGR1900+14 burst localized by HETE
  78. GRB020813: High-resolution optical spectroscopy
  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. GRB020819 : Optical observations at KISO
  86. GRB 020812: early time optical observation at Ouda Station
  87. GRB020813: VRI Decay Slopes
  88. GRB020813: Magellan BVRI Photometry
  89. GRB 020819 : OT candidate - confirmation of non variability
  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. IPN triangulation of GRB020819 (HETE 2275)
  94. GRB020813: optical and NIR observations
  95. GRB020813: Fading X-ray Afterglow Observed with Chandra
  96. GRB020813, UBVRI field calibration
  97. GRB 020813: addendum to GCN 1498
  98. GRB020813: V-band decay slope
  99. GRB020812: NIR observations
  100. GRB020813 IRAM millimeter observations

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