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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"

32532 results found.

  1. IPN triangulation of GRB021027 (single large error box)
  2. GRB021004, late-time optical observations
  3. IPN triangulation of GRB021027 (two large error boxes)
  4. GRB 021023: Infrared Imaging
  5. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  6. IPN triangulation of SGR1900+14, October 22 2002
  7. GRB 021004: optical observations
  8. GRB021004: Optical Observations
  9. GRB 020813; likely host galaxy.
  10. IPN triangulation of GRB021020 (smaller error box)
  11. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  12. GRB 021008, radio observations
  13. GRB 021016, optical observations
  14. GRB 021004: VRI observations at TNG: possible break
  15. GRB021016, optical observations
  16. GRB 021008, optical observations
  17. GRB021016(=H2397): A Long GRB Localized by HETE
  18. IPN triangulation of GRB021016 (area corrected)
  19. IPN triangulation of GRB021016 (small error box)
  20. GRB021004: Optical Observations
  21. IPN triangulation of GRB021013 (single error box)
  22. GRB 021004: optical spectroscopy on Oct 11
  23. IPN triangulation of GRB021013 (two small error boxes)
  24. GRB021004: High-resolution optical spectroscopy
  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 GRB021008 (two small error boxes)
  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. GRB021004: NIR and Optical observations
  38. GRB 021004: Optical measurement at OHP
  39. GRB 021004: Optical observations, AUDE network
  40. GRB 021004 - VLA Radio Observations
  41. GRB 021004 - Unusual Radio-to-Submm Spectrum
  42. XRF 020903 spectrum
  43. GRB021004: optical observations and predicted break time
  44. GRB021004: BVRc photometry
  45. GRB 021004 redshift
  46. GRB021004: restart of optical decay
  47. GRB 021004: Optical Decay
  48. GRB 021004, spectroscopic observations
  49. GRB021004: not fading anymore?
  50. GRB 021004: Optical Photometry at 2.5 Days
  51. GRB 021004: polarimetric observations
  52. GRB 021004: V-band Polarimetric Observations
  53. GRB021004: Update Bisei photometric data
  54. GRB 021004: Optical Decay
  55. GRB021004, astrometric position
  56. GRB021004, Optical Observations
  57. IRAM Millimeter detection of GRB 021004
  58. GRB 021004: Optical observations at RIKEN
  59. GRB 021004 radio observation
  60. GRB 021004: Optical Observations
  61. GRB021004: continued fading
  62. GRB 021004: Optical Photometry at 1.5 Days
  63. GRB021004, Optical Observations
  64. GRB021004, BVRcIc field photometry
  65. GRB 021004: Optical observations
  66. GRB 021004: optical counterpart
  67. GRB 021004, optical observations
  68. GRB021004: Optical Spectroscopy
  69. GRB 021004: Optical Observations
  70. GRB 021004, SPM optical observations
  71. GRB 021004, optical observations
  72. GRB 021004 radio search
  73. GRB 021004: radio observations
  74. GRB 021004: steepening of the optical decay slope
  75. GRB021004: Upper limits from recent and historical observations
  76. XRF020903, BVRI field photometry
  77. GRB021004: optical observations at Nyrola
  78. GRB021004: Absorption redshift
  79. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  80. GRB021004: optical observations at Bisei
  81. GRB 021004: Kyoto observation
  82. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  83. XRF020903: TNG and Asiago photometry
  84. GRB 020903: Optical observations at RIKEN
  85. XRF 020903: Correction to GCN 1560
  86. XRF 020903: VRI observations
  87. IPN triangulation of GRB020926 (single large error box)
  88. GRB 020903: correction to GCN 1557
  89. XRF 020903: R band observations
  90. XRF 020903: Archival Optical Images
  91. Radio Observations of XRF 020903: The Missing Link
  92. XRF 020903: Supernova
  93. GRB020924 (ecliptic latitude-only localization)
  94. IPN triangulation of GRB020923 (two error boxes)
  95. IPN triangulation of GRB020914B
  96. Improved IPN position for GRB020918 (two large error boxes)
  97. IPN annulus for GRB020914B
  98. IPN triangulation of GRB020914 - clarification and additional information
  99. IPN triangulation of GRB020914
  100. GRB 020305: HST/STIS observations

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