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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"

28054 results found.

  1. GRB 021004: optical spectroscopy on Oct 11
  2. IPN triangulation of GRB021013 (two small error boxes)
  3. GRB021004: High-resolution optical spectroscopy
  4. XRF 020903: flattening of the optical light curve.
  5. GRB021004, UBVRcIc field photometry update
  6. IPN triangulation of GRB021008 (single error box)
  7. GRB 021004 submm observations
  8. IPN triangulation of GRB021008 (two small error boxes)
  9. GRB021004 Chandra HETG Observations
  10. GRB 021004: Optical/NIR Observations
  11. GRB 021004: Additional V-band Polarimetric Observations
  12. GRB021004: optical observation
  13. GRB 021004: Host Galaxy Star Formation Rate
  14. GRB 021004 submm observations
  15. GRB 021004: WC wind?
  16. GRB021004: NIR and Optical observations
  17. GRB 021004: Optical observations, AUDE network
  18. GRB 021004 - VLA Radio Observations
  19. GRB 021004 - Unusual Radio-to-Submm Spectrum
  20. GRB 021004: optical spectroscopy
  21. IPN triangulation of GRB021007 (annulus)
  22. GRB021004: optical observations and predicted break time
  23. GRB021004: BVRc photometry
  24. GRB021004 radio observation
  25. HETE fluences for GRB021004
  26. GRB 021004: Optical Photometry at 2.5 Days
  27. GRB 021004: polarimetric observations
  28. GRB 021004: V-band Polarimetric Observations
  29. GRB021004: Update Bisei photometric data
  30. IRAM Millimeter detection of GRB 021004
  31. GRB 021004 radio observation
  32. GRB 021004: Optical Photometry at 1.5 Days
  33. GRB021004, BVRcIc field photometry
  34. GRB021004: Optical Spectroscopy
  35. GRB 021004 radio search
  36. XRF020903, BVRI field photometry
  37. XRF020903: TNG and Asiago photometry
  38. GRB 020903: Optical observations at RIKEN
  39. XRF 020903: Correction to GCN 1560
  40. XRF 020903: VRI observations
  41. XRF 020903: R band observations
  42. XRF 020903: Archival Optical Images
  43. Radio Observations of XRF 020903: The Missing Link
  44. XRF 020903: Supernova
  45. IPN triangulation of GRB020923 (two error boxes)
  46. IPN triangulation of GRB020914B
  47. IPN triangulation of GRB020911 (2 large error boxes)
  48. GRB 020305: HST/STIS observations
  49. Confirmation of IPN error box for GRB020910
  50. IPN triangulation of GRB020910
  51. IPN GCN Circulars now to be issued without restriction
  52. Single IPN error box for GRB020904
  53. XRF 020903: optical observation at Kyoto
  54. GRB020322 : HST/STIS observations
  55. XRF 020903: Optical observations
  56. IPN triangulation of GRB020904
  57. INTEGRAL GRBs added to GCN
  58. SGR1900+14 burst localized by HETE
  59. GRB020813: High-resolution optical spectroscopy
  60. GRB020812: negative optical observations
  61. GRB 020812: optical observation at Kyoto University
  62. Second epoch K band imaging of GRB 020819
  63. GRB 020813 : HST observations
  64. GRB 020812: early time optical observation at Ouda Station
  65. GRB020813: Magellan BVRI Photometry
  66. GRB 020819: Optical observations
  67. K band observation of GRB 020819
  68. GRB020813: optical and NIR observations
  69. GRB020813: Fading X-ray Afterglow Observed with Chandra
  70. GRB020813, UBVRI field calibration
  71. GRB020812: NIR observations
  72. Polarimetry of GRB020813: evidence for variability
  73. GRB020813 IRAM millimeter observations
  74. GRB020812: optical observations
  75. GRB020813: High-Resolution Optical Observations
  76. GRB 020812: optical observation at Bisei
  77. GRB020813: Early Time Magnitude
  78. Millimeter observation of GRB 020813
  79. GRB020812: optical observations
  80. GRB 020813 : KISO multiband optical observations
  81. GRB020813, optical observations
  82. IPN error box for GRB020813
  83. GRB020813, astrometric position
  84. Spectropolarimetry of GRB 020813
  85. GRB 020812 optical observation
  86. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  87. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  88. HST Imaging of the Host of GRB 011121
  89. GRB020801, optical afterglow candidate
  90. GRB020331: Late-time Optical Light Curve (re-submission)
  91. GRB020331: Late-time Optical Light Curve
  92. IPN triangulation of GRB020714
  93. IPN triangulation of GRB020715 (=GRB150702)
  94. IPN triangulation of GRB020714
  95. IPN triangulation of GRB150702
  96. GRB 020410: Discovery of Probable OT by HST
  97. GRB 020124, HST observations of the fading afterglow
  98. IPN triangulation of GRB020708
  99. IPN triangulation of GRB020708
  100. Correction to IPN error box for GRB020706

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