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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"

44623 results found.

  1. GRB021004: optical observation
  2. GRB 021004: Host Galaxy Star Formation Rate
  3. GRB 021004 submm observations
  4. GRB 021004: WC wind?
  5. IPN triangulation of GRB021008
  6. GRB021004: NIR and Optical observations
  7. GRB 021004: Optical measurement at OHP
  8. GRB 021004: Optical observations, AUDE network
  9. GRB 021004 - VLA Radio Observations
  10. GRB 021004 - Unusual Radio-to-Submm Spectrum
  11. GRB 021004: optical spectroscopy
  12. IPN triangulation of GRB021007 (annulus)
  13. XRF 020903 spectrum
  14. GRB 021004: HST/STIS spectroscopic observations
  15. GRB021004: optical observations and predicted break time
  16. GRB021004: BVRc photometry
  17. GRB 021004 redshift
  18. GRB021004 radio observation
  19. GRB021004: restart of optical decay
  20. GRB 021004: Optical Decay
  21. GRB 021004 continued IR fading
  22. HETE fluences for GRB021004
  23. GRB 021004, spectroscopic observations
  24. GRB021004: not fading anymore?
  25. GRB 021004: Optical Photometry at 2.5 Days
  26. GRB 021004: polarimetric observations
  27. GRB 021004: V-band Polarimetric Observations
  28. GRB021004: Update Bisei photometric data
  29. GRB 021004: Optical Decay
  30. GRB021004, astrometric position
  31. GRB021004, Optical Observations
  32. IRAM Millimeter detection of GRB 021004
  33. GRB 021004: Optical observations at RIKEN
  34. GRB 021004 radio observation
  35. GRB 021004: Optical Observations
  36. GRB021004: continued fading
  37. GRB 021004: Optical Photometry at 1.5 Days
  38. GRB021004, Optical Observations
  39. GRB021004, BVRcIc field photometry
  40. GRB 021004: Optical observations
  41. GRB 021004: optical counterpart
  42. GRB 021004, optical observations
  43. GRB021004: Optical Spectroscopy
  44. GRB 021004: Optical Observations
  45. GRB 021004, SPM optical observations
  46. GRB 021004, optical observations
  47. GRB 021004 radio search
  48. GRB 021004: radio observations
  49. GRB 021004: steepening of the optical decay slope
  50. GRB021004: Upper limits from recent and historical observations
  51. XRF020903, BVRI field photometry
  52. GRB021004: optical observations at Nyrola
  53. GRB021004: Absorption redshift
  54. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  55. GRB021004: optical observations at Bisei
  56. GRB 021004: Kyoto observation
  57. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  58. GRB021004: Optical Afterglow
  59. XRF020903: TNG and Asiago photometry
  60. GRB 020903: Optical observations at RIKEN
  61. XRF 020903: Correction to GCN 1560
  62. XRF 020903: VRI observations
  63. IPN triangulation of GRB020926 (single large error box)
  64. GRB 020903: correction to GCN 1557
  65. XRF 020903: R band observations
  66. XRF 020903: Archival Optical Images
  67. Radio Observations of XRF 020903: The Missing Link
  68. XRF 020903: Supernova
  69. IPN triangulation of GRB020926 (two large error boxes)
  70. GRB020924 (ecliptic latitude-only localization)
  71. IPN triangulation of GRB020923 (two error boxes)
  72. IPN annulus for GRB020923
  73. IPN triangulation of GRB020914B
  74. Improved IPN position for GRB020918 (two large error boxes)
  75. IPN annulus for GRB020914B
  76. IPN triangulation of GRB020918 (annulus)
  77. IPN triangulation of GRB020911 (2 large error boxes)
  78. IPN triangulation of GRB020914 - clarification and additional information
  79. IPN triangulation of GRB020914
  80. GRB 020305: HST/STIS observations
  81. Confirmation of IPN error box for GRB020910
  82. IPN triangulation of GRB020910
  83. IPN GCN Circulars now to be issued without restriction
  84. Single IPN error box for GRB020904
  85. XRF 020903: optical observation at Kyoto
  86. GRB020322 : HST/STIS observations
  87. XRF 020903: Optical observations
  88. IPN triangulation of GRB020904
  89. XRF 020903: Optical observations
  90. IPN detection of a burst from SGR1900+14
  91. XRF 020903, optical observations
  92. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  93. INTEGRAL GRBs added to GCN
  94. GRB020813: optical observation
  95. GRB020812: optical observation
  96. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  97. SGR1900+14 burst localized by HETE
  98. GRB020813: High-resolution optical spectroscopy
  99. GRB020819: optical observations at Bisei
  100. GRB020812: negative optical observations

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