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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"

45433 results found.

  1. IPN triangulation of GRB021023 (small error boc)
  2. GRB021004: Optical Observations
  3. GRB 020813; likely host galaxy.
  4. IPN triangulation of GRB021020 (smaller error box)
  5. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  6. IPN triangulation of GRB021020
  7. GRB 021008, radio observations
  8. GRB 021016, optical observations
  9. GRB 021004: VRI observations at TNG: possible break
  10. GRB021016, optical observations
  11. SGR1900+14: burst on October 10 2002
  12. GRB 021008, optical observations
  13. GRB021016(=H2397): A Long GRB Localized by HETE
  14. IPN triangulation of GRB021016 (area corrected)
  15. IPN triangulation of GRB021016 (small error box)
  16. GRB021004: Optical Observations
  17. IPN triangulation of GRB021014 (large error box)
  18. IPN triangulation of GRB021013 (single error box)
  19. GRB 021004: optical spectroscopy on Oct 11
  20. IPN triangulation of GRB021013 (two small error boxes)
  21. GRB021004: High-resolution optical spectroscopy
  22. IPN triangulation of GRB021013 (annulus)
  23. XRF 020903: flattening of the optical light curve.
  24. GRB021004, UBVRcIc field photometry update
  25. IPN triangulation of GRB021008 (single error box)
  26. GRB021004: Optical Observations
  27. GRB 021004 submm observations
  28. IPN triangulation of GRB021008B (annulus)
  29. IPN triangulation of GRB021008 (two small error boxes)
  30. GRB021004 Chandra HETG Observations
  31. GRB 021004: Optical/NIR Observations
  32. GRB 021004: Additional V-band Polarimetric Observations
  33. GRB021004: optical observation
  34. GRB 021004: Host Galaxy Star Formation Rate
  35. GRB 021004 submm observations
  36. GRB 021004: WC wind?
  37. IPN triangulation of GRB021008
  38. GRB021004: NIR and Optical observations
  39. GRB 021004: Optical measurement at OHP
  40. GRB 021004: Optical observations, AUDE network
  41. GRB 021004 - VLA Radio Observations
  42. GRB 021004 - Unusual Radio-to-Submm Spectrum
  43. GRB 021004: optical spectroscopy
  44. IPN triangulation of GRB021007 (annulus)
  45. XRF 020903 spectrum
  46. GRB 021004: HST/STIS spectroscopic observations
  47. GRB021004: optical observations and predicted break time
  48. GRB021004: BVRc photometry
  49. GRB 021004 redshift
  50. GRB021004 radio observation
  51. GRB021004: restart of optical decay
  52. GRB 021004: Optical Decay
  53. GRB 021004 continued IR fading
  54. HETE fluences for GRB021004
  55. GRB 021004, spectroscopic observations
  56. GRB021004: not fading anymore?
  57. GRB 021004: Optical Photometry at 2.5 Days
  58. GRB 021004: polarimetric observations
  59. GRB 021004: V-band Polarimetric Observations
  60. GRB021004: Update Bisei photometric data
  61. GRB 021004: Optical Decay
  62. GRB021004, astrometric position
  63. GRB021004, Optical Observations
  64. IRAM Millimeter detection of GRB 021004
  65. GRB 021004: Optical observations at RIKEN
  66. GRB 021004 radio observation
  67. GRB 021004: Optical Observations
  68. GRB021004: continued fading
  69. GRB 021004: Optical Photometry at 1.5 Days
  70. GRB021004, Optical Observations
  71. GRB021004, BVRcIc field photometry
  72. GRB 021004: Optical observations
  73. GRB 021004: optical counterpart
  74. GRB 021004, optical observations
  75. GRB021004: Optical Spectroscopy
  76. GRB 021004: Optical Observations
  77. GRB 021004, SPM optical observations
  78. GRB 021004, optical observations
  79. GRB 021004 radio search
  80. GRB 021004: radio observations
  81. GRB 021004: steepening of the optical decay slope
  82. GRB021004: Upper limits from recent and historical observations
  83. XRF020903, BVRI field photometry
  84. GRB021004: optical observations at Nyrola
  85. GRB021004: Absorption redshift
  86. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  87. GRB021004: optical observations at Bisei
  88. GRB 021004: Kyoto observation
  89. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  90. GRB021004: Optical Afterglow
  91. XRF020903: TNG and Asiago photometry
  92. GRB 020903: Optical observations at RIKEN
  93. XRF 020903: Correction to GCN 1560
  94. XRF 020903: VRI observations
  95. IPN triangulation of GRB020926 (single large error box)
  96. GRB 020903: correction to GCN 1557
  97. XRF 020903: R band observations
  98. XRF 020903: Archival Optical Images
  99. Radio Observations of XRF 020903: The Missing Link
  100. XRF 020903: Supernova

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