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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"

28059 results found.

  1. IPN triangulation of GRB021020
  2. GRB 021008, optical observations
  3. IPN triangulation of GRB021016 (small error box)
  4. IPN triangulation of GRB021014 (large error box)
  5. IPN triangulation of GRB021013 (single error box)
  6. GRB 021004: optical spectroscopy on Oct 11
  7. IPN triangulation of GRB021013 (two small error boxes)
  8. GRB021004: High-resolution optical spectroscopy
  9. XRF 020903: flattening of the optical light curve.
  10. GRB021004, UBVRcIc field photometry update
  11. IPN triangulation of GRB021008 (single error box)
  12. GRB 021004 submm observations
  13. IPN triangulation of GRB021008 (two small error boxes)
  14. GRB021004 Chandra HETG Observations
  15. GRB 021004: Optical/NIR Observations
  16. GRB 021004: Additional V-band Polarimetric Observations
  17. GRB021004: optical observation
  18. GRB 021004: Host Galaxy Star Formation Rate
  19. GRB 021004 submm observations
  20. GRB 021004: WC wind?
  21. GRB021004: NIR and Optical observations
  22. GRB 021004: Optical observations, AUDE network
  23. GRB 021004 - VLA Radio Observations
  24. GRB 021004 - Unusual Radio-to-Submm Spectrum
  25. GRB 021004: optical spectroscopy
  26. IPN triangulation of GRB021007 (annulus)
  27. GRB021004: optical observations and predicted break time
  28. GRB021004: BVRc photometry
  29. GRB021004 radio observation
  30. HETE fluences for GRB021004
  31. GRB 021004: Optical Photometry at 2.5 Days
  32. GRB 021004: polarimetric observations
  33. GRB 021004: V-band Polarimetric Observations
  34. GRB021004: Update Bisei photometric data
  35. IRAM Millimeter detection of GRB 021004
  36. GRB 021004 radio observation
  37. GRB 021004: Optical Photometry at 1.5 Days
  38. GRB021004, BVRcIc field photometry
  39. GRB021004: Optical Spectroscopy
  40. GRB 021004 radio search
  41. XRF020903, BVRI field photometry
  42. XRF020903: TNG and Asiago photometry
  43. GRB 020903: Optical observations at RIKEN
  44. XRF 020903: Correction to GCN 1560
  45. XRF 020903: VRI observations
  46. XRF 020903: R band observations
  47. XRF 020903: Archival Optical Images
  48. Radio Observations of XRF 020903: The Missing Link
  49. XRF 020903: Supernova
  50. IPN triangulation of GRB020923 (two error boxes)
  51. IPN triangulation of GRB020914B
  52. IPN triangulation of GRB020911 (2 large error boxes)
  53. GRB 020305: HST/STIS observations
  54. Confirmation of IPN error box for GRB020910
  55. IPN triangulation of GRB020910
  56. IPN GCN Circulars now to be issued without restriction
  57. Single IPN error box for GRB020904
  58. XRF 020903: optical observation at Kyoto
  59. GRB020322 : HST/STIS observations
  60. XRF 020903: Optical observations
  61. IPN triangulation of GRB020904
  62. INTEGRAL GRBs added to GCN
  63. SGR1900+14 burst localized by HETE
  64. GRB020813: High-resolution optical spectroscopy
  65. GRB020812: negative optical observations
  66. GRB 020812: optical observation at Kyoto University
  67. Second epoch K band imaging of GRB 020819
  68. GRB 020813 : HST observations
  69. GRB 020812: early time optical observation at Ouda Station
  70. GRB020813: Magellan BVRI Photometry
  71. GRB 020819: Optical observations
  72. K band observation of GRB 020819
  73. GRB020813: optical and NIR observations
  74. GRB020813: Fading X-ray Afterglow Observed with Chandra
  75. GRB020813, UBVRI field calibration
  76. GRB020812: NIR observations
  77. Polarimetry of GRB020813: evidence for variability
  78. GRB020813 IRAM millimeter observations
  79. GRB020812: optical observations
  80. GRB020813: High-Resolution Optical Observations
  81. GRB 020812: optical observation at Bisei
  82. GRB020813: Early Time Magnitude
  83. Millimeter observation of GRB 020813
  84. GRB020812: optical observations
  85. GRB 020813 : KISO multiband optical observations
  86. GRB020813, optical observations
  87. IPN error box for GRB020813
  88. GRB020813, astrometric position
  89. Spectropolarimetry of GRB 020813
  90. GRB 020812 optical observation
  91. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  92. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  93. HST Imaging of the Host of GRB 011121
  94. GRB020801, optical afterglow candidate
  95. GRB020331: Late-time Optical Light Curve (re-submission)
  96. GRB020331: Late-time Optical Light Curve
  97. IPN triangulation of GRB020714
  98. IPN triangulation of GRB020715 (=GRB150702)
  99. IPN triangulation of GRB020714
  100. IPN triangulation of GRB150702

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