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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"

36364 results found.

  1. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  2. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  3. IPN triangulation of GRB021025 (portion of annulus)
  4. IPN triangulation of GRB021027 (single large error box)
  5. GRB021004, late-time optical observations
  6. IPN triangulation of GRB021027 (two large error boxes)
  7. GRB 021023: Infrared Imaging
  8. IPN triangulation of GRB021027 (annulus)
  9. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  10. IPN triangulation of GRB021025 (annulus)
  11. IPN triangulation of SGR1900+14, October 22 2002
  12. GRB 021004: optical observations
  13. IPN triangulation of GRB021023 (small error boc)
  14. GRB 020813; likely host galaxy.
  15. IPN triangulation of GRB021020 (smaller error box)
  16. IPN triangulation of GRB021020
  17. GRB 021008, radio observations
  18. GRB 021016, optical observations
  19. GRB 021004: VRI observations at TNG: possible break
  20. GRB021016, optical observations
  21. SGR1900+14: burst on October 10 2002
  22. GRB 021008, optical observations
  23. GRB021016(=H2397): A Long GRB Localized by HETE
  24. IPN triangulation of GRB021016 (small error box)
  25. IPN triangulation of GRB021014 (large error box)
  26. IPN triangulation of GRB021013 (single error box)
  27. GRB 021004: optical spectroscopy on Oct 11
  28. IPN triangulation of GRB021013 (two small error boxes)
  29. GRB021004: High-resolution optical spectroscopy
  30. IPN triangulation of GRB021013 (annulus)
  31. XRF 020903: flattening of the optical light curve.
  32. GRB021004, UBVRcIc field photometry update
  33. IPN triangulation of GRB021008 (single error box)
  34. GRB 021004 submm observations
  35. IPN triangulation of GRB021008B (annulus)
  36. IPN triangulation of GRB021008 (two small error boxes)
  37. GRB 021004: Optical/NIR Observations
  38. GRB 021004: Additional V-band Polarimetric Observations
  39. GRB021004: optical observation
  40. GRB 021004: Host Galaxy Star Formation Rate
  41. GRB 021004 submm observations
  42. GRB 021004: WC wind?
  43. IPN triangulation of GRB021008
  44. GRB 021004: Optical measurement at OHP
  45. GRB 021004: Optical observations, AUDE network
  46. GRB 021004 - VLA Radio Observations
  47. GRB 021004 - Unusual Radio-to-Submm Spectrum
  48. GRB 021004: optical spectroscopy
  49. IPN triangulation of GRB021007 (annulus)
  50. GRB 021004: HST/STIS spectroscopic observations
  51. GRB021004: optical observations and predicted break time
  52. GRB 021004 redshift
  53. GRB 021004: Optical Decay
  54. GRB 021004 continued IR fading
  55. HETE fluences for GRB021004
  56. GRB 021004, spectroscopic observations
  57. GRB021004: not fading anymore?
  58. GRB 021004: Optical Photometry at 2.5 Days
  59. GRB 021004: polarimetric observations
  60. GRB 021004: V-band Polarimetric Observations
  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. GRB 021004: Kyoto observation
  87. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  88. GRB021004: Optical Afterglow
  89. GRB 020903: Optical observations at RIKEN
  90. IPN triangulation of GRB020926 (single large error box)
  91. GRB 020903: correction to GCN 1557
  92. XRF 020903: R band observations
  93. Radio Observations of XRF 020903: The Missing Link
  94. XRF 020903: Supernova
  95. IPN triangulation of GRB020926 (two large error boxes)
  96. GRB020924 (ecliptic latitude-only localization)
  97. IPN triangulation of GRB020923 (two error boxes)
  98. IPN annulus for GRB020923
  99. IPN triangulation of GRB020914B
  100. Improved IPN position for GRB020918 (two large error boxes)

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