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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"

32533 results found.

  1. IPN triangulation of GRB021025 (portion of annulus)
  2. IPN triangulation of GRB021027 (single large error box)
  3. GRB021004, late-time optical observations
  4. IPN triangulation of GRB021027 (two large error boxes)
  5. GRB 021023: Infrared Imaging
  6. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  7. IPN triangulation of SGR1900+14, October 22 2002
  8. GRB 021004: optical observations
  9. GRB021004: Optical Observations
  10. GRB 020813; likely host galaxy.
  11. IPN triangulation of GRB021020 (smaller error box)
  12. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  13. GRB 021008, radio observations
  14. GRB 021016, optical observations
  15. GRB 021004: VRI observations at TNG: possible break
  16. GRB021016, optical observations
  17. GRB 021008, optical observations
  18. GRB021016(=H2397): A Long GRB Localized by HETE
  19. IPN triangulation of GRB021016 (area corrected)
  20. IPN triangulation of GRB021016 (small error box)
  21. GRB021004: Optical Observations
  22. IPN triangulation of GRB021013 (single error box)
  23. GRB 021004: optical spectroscopy on Oct 11
  24. IPN triangulation of GRB021013 (two small error boxes)
  25. GRB021004: High-resolution optical spectroscopy
  26. XRF 020903: flattening of the optical light curve.
  27. GRB021004, UBVRcIc field photometry update
  28. IPN triangulation of GRB021008 (single error box)
  29. GRB021004: Optical Observations
  30. GRB 021004 submm observations
  31. IPN triangulation of GRB021008 (two small error boxes)
  32. GRB 021004: Optical/NIR Observations
  33. GRB 021004: Additional V-band Polarimetric Observations
  34. GRB021004: optical observation
  35. GRB 021004: Host Galaxy Star Formation Rate
  36. GRB 021004 submm observations
  37. GRB 021004: WC wind?
  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. XRF 020903 spectrum
  44. GRB021004: optical observations and predicted break time
  45. GRB021004: BVRc photometry
  46. GRB 021004 redshift
  47. GRB021004: restart of optical decay
  48. GRB 021004: Optical Decay
  49. GRB 021004, spectroscopic observations
  50. GRB021004: not fading anymore?
  51. GRB 021004: Optical Photometry at 2.5 Days
  52. GRB 021004: polarimetric observations
  53. GRB 021004: V-band Polarimetric Observations
  54. GRB021004: Update Bisei photometric data
  55. GRB 021004: Optical Decay
  56. GRB021004, astrometric position
  57. GRB021004, Optical Observations
  58. IRAM Millimeter detection of GRB 021004
  59. GRB 021004: Optical observations at RIKEN
  60. GRB 021004 radio observation
  61. GRB 021004: Optical Observations
  62. GRB021004: continued fading
  63. GRB 021004: Optical Photometry at 1.5 Days
  64. GRB021004, Optical Observations
  65. GRB021004, BVRcIc field photometry
  66. GRB 021004: Optical observations
  67. GRB 021004: optical counterpart
  68. GRB 021004, optical observations
  69. GRB021004: Optical Spectroscopy
  70. GRB 021004: Optical Observations
  71. GRB 021004, SPM optical observations
  72. GRB 021004, optical observations
  73. GRB 021004 radio search
  74. GRB 021004: radio observations
  75. GRB 021004: steepening of the optical decay slope
  76. GRB021004: Upper limits from recent and historical observations
  77. XRF020903, BVRI field photometry
  78. GRB021004: optical observations at Nyrola
  79. GRB021004: Absorption redshift
  80. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  81. GRB021004: optical observations at Bisei
  82. GRB 021004: Kyoto observation
  83. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  84. XRF020903: TNG and Asiago photometry
  85. GRB 020903: Optical observations at RIKEN
  86. XRF 020903: Correction to GCN 1560
  87. XRF 020903: VRI observations
  88. IPN triangulation of GRB020926 (single large error box)
  89. GRB 020903: correction to GCN 1557
  90. XRF 020903: R band observations
  91. XRF 020903: Archival Optical Images
  92. Radio Observations of XRF 020903: The Missing Link
  93. XRF 020903: Supernova
  94. GRB020924 (ecliptic latitude-only localization)
  95. IPN triangulation of GRB020923 (two error boxes)
  96. IPN triangulation of GRB020914B
  97. Improved IPN position for GRB020918 (two large error boxes)
  98. IPN annulus for GRB020914B
  99. IPN triangulation of GRB020914 - clarification and additional information
  100. IPN triangulation of GRB020914

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