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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"

39220 results found.

  1. IPN triangulation of GRB021016 (small error box)
  2. IPN triangulation of GRB021014 (large error box)
  3. IPN triangulation of GRB021013 (single error box)
  4. GRB 021004: optical spectroscopy on Oct 11
  5. IPN triangulation of GRB021013 (two small error boxes)
  6. GRB021004: High-resolution optical spectroscopy
  7. IPN triangulation of GRB021013 (annulus)
  8. GRB021004, UBVRcIc field photometry update
  9. IPN triangulation of GRB021008 (single error box)
  10. GRB 021004 submm observations
  11. IPN triangulation of GRB021008B (annulus)
  12. IPN triangulation of GRB021008 (two small error boxes)
  13. GRB 021004: Optical/NIR Observations
  14. GRB 021004: Additional V-band Polarimetric Observations
  15. GRB021004: optical observation
  16. GRB 021004: Host Galaxy Star Formation Rate
  17. GRB 021004 submm observations
  18. GRB 021004: WC wind?
  19. IPN triangulation of GRB021008
  20. GRB 021004: Optical measurement at OHP
  21. GRB 021004: Optical observations, AUDE network
  22. GRB 021004 - VLA Radio Observations
  23. GRB 021004 - Unusual Radio-to-Submm Spectrum
  24. GRB 021004: optical spectroscopy
  25. IPN triangulation of GRB021007 (annulus)
  26. GRB 021004: HST/STIS spectroscopic observations
  27. GRB021004: optical observations and predicted break time
  28. GRB 021004 redshift
  29. GRB 021004: Optical Decay
  30. GRB 021004 continued IR fading
  31. HETE fluences for GRB021004
  32. GRB 021004, spectroscopic observations
  33. GRB021004: not fading anymore?
  34. GRB 021004: Optical Photometry at 2.5 Days
  35. GRB 021004: polarimetric observations
  36. GRB 021004: V-band Polarimetric Observations
  37. GRB 021004: Optical Decay
  38. GRB021004, astrometric position
  39. GRB021004, Optical Observations
  40. IRAM Millimeter detection of GRB 021004
  41. GRB 021004: Optical observations at RIKEN
  42. GRB 021004 radio observation
  43. GRB 021004: Optical Observations
  44. GRB021004: continued fading
  45. GRB 021004: Optical Photometry at 1.5 Days
  46. GRB021004, Optical Observations
  47. GRB021004, BVRcIc field photometry
  48. GRB 021004: Optical observations
  49. GRB 021004: optical counterpart
  50. GRB 021004, optical observations
  51. GRB021004: Optical Spectroscopy
  52. GRB 021004: Optical Observations
  53. GRB 021004, SPM optical observations
  54. GRB 021004, optical observations
  55. GRB 021004 radio search
  56. GRB 021004: radio observations
  57. GRB 021004: steepening of the optical decay slope
  58. GRB021004: Upper limits from recent and historical observations
  59. XRF020903, BVRI field photometry
  60. GRB021004: optical observations at Nyrola
  61. GRB021004: Absorption redshift
  62. GRB 021004: Kyoto observation
  63. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  64. GRB021004: Optical Afterglow
  65. GRB 020903: Optical observations at RIKEN
  66. IPN triangulation of GRB020926 (single large error box)
  67. GRB 020903: correction to GCN 1557
  68. XRF 020903: R band observations
  69. Radio Observations of XRF 020903: The Missing Link
  70. XRF 020903: Supernova
  71. IPN triangulation of GRB020926 (two large error boxes)
  72. GRB020924 (ecliptic latitude-only localization)
  73. IPN triangulation of GRB020923 (two error boxes)
  74. IPN annulus for GRB020923
  75. IPN triangulation of GRB020914B
  76. Improved IPN position for GRB020918 (two large error boxes)
  77. IPN annulus for GRB020914B
  78. IPN triangulation of GRB020918 (annulus)
  79. IPN triangulation of GRB020911 (2 large error boxes)
  80. IPN triangulation of GRB020914 - clarification and additional information
  81. IPN triangulation of GRB020914
  82. GRB 020305: HST/STIS observations
  83. Confirmation of IPN error box for GRB020910
  84. IPN triangulation of GRB020910
  85. IPN GCN Circulars now to be issued without restriction
  86. Single IPN error box for GRB020904
  87. XRF 020903: optical observation at Kyoto
  88. GRB020322 : HST/STIS observations
  89. IPN triangulation of GRB020904
  90. IPN detection of a burst from SGR1900+14
  91. INTEGRAL GRBs added to GCN
  92. GRB020813: High-resolution optical spectroscopy
  93. GRB 020812: optical observation at Kyoto University
  94. Second epoch K band imaging of GRB 020819
  95. GRB020813, Baade 6.5m data now available
  96. GRB 020813 : HST observations
  97. Confirming no variability for GRB02081
  98. GRB020819 : Optical observations at KISO
  99. GRB 020812: early time optical observation at Ouda Station
  100. GRB020813: VRI Decay Slopes

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