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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"

45435 results found.

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

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