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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"
  1. GRB 021023: Infrared Imaging
  2. IPN triangulation of GRB021027 (annulus)
  3. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  4. IPN triangulation of GRB021025 (annulus)
  5. IPN triangulation of SGR1900+14, October 22 2002
  6. GRB 021004: optical observations
  7. IPN triangulation of GRB021023 (small error boc)
  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. IPN triangulation of GRB021020
  13. GRB 021008, radio observations
  14. GRB 021016, optical observations
  15. GRB 021004: VRI observations at TNG: possible break
  16. GRB021016, optical observations
  17. SGR1900+14: burst on October 10 2002
  18. GRB 021008, optical observations
  19. GRB021016(=H2397): A Long GRB Localized by HETE
  20. IPN triangulation of GRB021016 (area corrected)
  21. IPN triangulation of GRB021016 (small error box)
  22. GRB021004: Optical Observations
  23. IPN triangulation of GRB021014 (large error box)
  24. IPN triangulation of GRB021013 (single error box)
  25. GRB 021004: optical spectroscopy on Oct 11
  26. IPN triangulation of GRB021013 (two small error boxes)
  27. GRB021004: High-resolution optical spectroscopy
  28. IPN triangulation of GRB021013 (annulus)
  29. XRF 020903: flattening of the optical light curve.
  30. GRB021004, UBVRcIc field photometry update
  31. IPN triangulation of GRB021008 (single error box)
  32. GRB021004: Optical Observations
  33. GRB 021004 submm observations
  34. IPN triangulation of GRB021008B (annulus)
  35. IPN triangulation of GRB021008 (two small error boxes)
  36. GRB021004 Chandra HETG Observations
  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. GRB021004: NIR and Optical observations
  45. GRB 021004: Optical measurement at OHP
  46. GRB 021004: Optical observations, AUDE network
  47. GRB 021004 - VLA Radio Observations
  48. GRB 021004 - Unusual Radio-to-Submm Spectrum
  49. GRB 021004: optical spectroscopy
  50. IPN triangulation of GRB021007 (annulus)
  51. XRF 020903 spectrum
  52. GRB 021004: HST/STIS spectroscopic observations
  53. GRB021004: optical observations and predicted break time
  54. GRB021004: BVRc photometry
  55. GRB 021004 redshift
  56. GRB021004 radio observation
  57. GRB021004: restart of optical decay
  58. GRB 021004: Optical Decay
  59. GRB 021004 continued IR fading
  60. HETE fluences for GRB021004
  61. GRB 021004, spectroscopic observations
  62. GRB021004: not fading anymore?
  63. GRB 021004: Optical Photometry at 2.5 Days
  64. GRB 021004: polarimetric observations
  65. GRB 021004: V-band Polarimetric Observations
  66. GRB021004: Update Bisei photometric data
  67. GRB 021004: Optical Decay
  68. GRB021004, astrometric position
  69. GRB021004, Optical Observations
  70. IRAM Millimeter detection of GRB 021004
  71. GRB 021004: Optical observations at RIKEN
  72. GRB 021004 radio observation
  73. GRB 021004: Optical Observations
  74. GRB021004: continued fading
  75. GRB 021004: Optical Photometry at 1.5 Days
  76. GRB021004, Optical Observations
  77. GRB021004, BVRcIc field photometry
  78. GRB 021004: Optical observations
  79. GRB 021004: optical counterpart
  80. GRB 021004, optical observations
  81. GRB021004: Optical Spectroscopy
  82. GRB 021004: Optical Observations
  83. GRB 021004, SPM optical observations
  84. GRB 021004, optical observations
  85. GRB 021004 radio search
  86. GRB 021004: radio observations
  87. GRB 021004: steepening of the optical decay slope
  88. GRB021004: Upper limits from recent and historical observations
  89. XRF020903, BVRI field photometry
  90. GRB021004: optical observations at Nyrola
  91. GRB021004: Absorption redshift
  92. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  93. GRB021004: optical observations at Bisei
  94. GRB 021004: Kyoto observation
  95. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  96. GRB021004: Optical Afterglow
  97. XRF020903: TNG and Asiago photometry
  98. GRB 020903: Optical observations at RIKEN
  99. XRF 020903: Correction to GCN 1560
  100. XRF 020903: VRI observations

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