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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"

37507 results found.

  1. IPN triangulation of GRB021025 (annulus)
  2. IPN triangulation of SGR1900+14, October 22 2002
  3. GRB 021004: optical observations
  4. IPN triangulation of GRB021023 (small error boc)
  5. GRB 020813; likely host galaxy.
  6. IPN triangulation of GRB021020 (smaller error box)
  7. IPN triangulation of GRB021020
  8. GRB 021008, radio observations
  9. GRB 021016, optical observations
  10. GRB 021004: VRI observations at TNG: possible break
  11. GRB021016, optical observations
  12. SGR1900+14: burst on October 10 2002
  13. GRB 021008, optical observations
  14. GRB021016(=H2397): A Long GRB Localized by HETE
  15. IPN triangulation of GRB021016 (small error box)
  16. IPN triangulation of GRB021014 (large error box)
  17. IPN triangulation of GRB021013 (single error box)
  18. GRB 021004: optical spectroscopy on Oct 11
  19. IPN triangulation of GRB021013 (two small error boxes)
  20. GRB021004: High-resolution optical spectroscopy
  21. IPN triangulation of GRB021013 (annulus)
  22. GRB021004, UBVRcIc field photometry update
  23. IPN triangulation of GRB021008 (single error box)
  24. GRB 021004 submm observations
  25. IPN triangulation of GRB021008B (annulus)
  26. IPN triangulation of GRB021008 (two small error boxes)
  27. GRB 021004: Optical/NIR Observations
  28. GRB 021004: Additional V-band Polarimetric Observations
  29. GRB021004: optical observation
  30. GRB 021004: Host Galaxy Star Formation Rate
  31. GRB 021004 submm observations
  32. GRB 021004: WC wind?
  33. IPN triangulation of GRB021008
  34. GRB 021004: Optical measurement at OHP
  35. GRB 021004: Optical observations, AUDE network
  36. GRB 021004 - VLA Radio Observations
  37. GRB 021004 - Unusual Radio-to-Submm Spectrum
  38. GRB 021004: optical spectroscopy
  39. IPN triangulation of GRB021007 (annulus)
  40. GRB 021004: HST/STIS spectroscopic observations
  41. GRB021004: optical observations and predicted break time
  42. GRB 021004 redshift
  43. GRB 021004: Optical Decay
  44. GRB 021004 continued IR fading
  45. HETE fluences for GRB021004
  46. GRB 021004, spectroscopic observations
  47. GRB021004: not fading anymore?
  48. GRB 021004: Optical Photometry at 2.5 Days
  49. GRB 021004: polarimetric observations
  50. GRB 021004: V-band Polarimetric Observations
  51. GRB 021004: Optical Decay
  52. GRB021004, astrometric position
  53. GRB021004, Optical Observations
  54. IRAM Millimeter detection of GRB 021004
  55. GRB 021004: Optical observations at RIKEN
  56. GRB 021004 radio observation
  57. GRB 021004: Optical Observations
  58. GRB021004: continued fading
  59. GRB 021004: Optical Photometry at 1.5 Days
  60. GRB021004, Optical Observations
  61. GRB021004, BVRcIc field photometry
  62. GRB 021004: Optical observations
  63. GRB 021004: optical counterpart
  64. GRB 021004, optical observations
  65. GRB021004: Optical Spectroscopy
  66. GRB 021004: Optical Observations
  67. GRB 021004, SPM optical observations
  68. GRB 021004, optical observations
  69. GRB 021004 radio search
  70. GRB 021004: radio observations
  71. GRB 021004: steepening of the optical decay slope
  72. GRB021004: Upper limits from recent and historical observations
  73. XRF020903, BVRI field photometry
  74. GRB021004: optical observations at Nyrola
  75. GRB021004: Absorption redshift
  76. GRB 021004: Kyoto observation
  77. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  78. GRB021004: Optical Afterglow
  79. GRB 020903: Optical observations at RIKEN
  80. IPN triangulation of GRB020926 (single large error box)
  81. GRB 020903: correction to GCN 1557
  82. XRF 020903: R band observations
  83. Radio Observations of XRF 020903: The Missing Link
  84. IPN triangulation of GRB020926 (two large error boxes)
  85. GRB020924 (ecliptic latitude-only localization)
  86. IPN triangulation of GRB020923 (two error boxes)
  87. IPN annulus for GRB020923
  88. IPN triangulation of GRB020914B
  89. Improved IPN position for GRB020918 (two large error boxes)
  90. IPN annulus for GRB020914B
  91. IPN triangulation of GRB020918 (annulus)
  92. IPN triangulation of GRB020911 (2 large error boxes)
  93. IPN triangulation of GRB020914 - clarification and additional information
  94. IPN triangulation of GRB020914
  95. GRB 020305: HST/STIS observations
  96. Confirmation of IPN error box for GRB020910
  97. IPN triangulation of GRB020910
  98. IPN GCN Circulars now to be issued without restriction
  99. Single IPN error box for GRB020904
  100. XRF 020903: optical observation at Kyoto

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