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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"

28058 results found.

  1. GRB 021008, optical observations
  2. IPN triangulation of GRB021016 (small error box)
  3. IPN triangulation of GRB021014 (large error box)
  4. IPN triangulation of GRB021013 (single error box)
  5. GRB 021004: optical spectroscopy on Oct 11
  6. IPN triangulation of GRB021013 (two small error boxes)
  7. GRB021004: High-resolution optical spectroscopy
  8. XRF 020903: flattening of the optical light curve.
  9. GRB021004, UBVRcIc field photometry update
  10. IPN triangulation of GRB021008 (single error box)
  11. GRB 021004 submm observations
  12. IPN triangulation of GRB021008 (two small error boxes)
  13. GRB021004 Chandra HETG Observations
  14. GRB 021004: Optical/NIR Observations
  15. GRB 021004: Additional V-band Polarimetric Observations
  16. GRB021004: optical observation
  17. GRB 021004: Host Galaxy Star Formation Rate
  18. GRB 021004 submm observations
  19. GRB 021004: WC wind?
  20. GRB021004: NIR and Optical observations
  21. GRB 021004: Optical observations, AUDE network
  22. GRB 021004 - VLA Radio Observations
  23. GRB 021004 - Unusual Radio-to-Submm Spectrum
  24. GRB 021004: optical spectroscopy
  25. IPN triangulation of GRB021007 (annulus)
  26. GRB021004: optical observations and predicted break time
  27. GRB021004: BVRc photometry
  28. GRB021004 radio observation
  29. HETE fluences for GRB021004
  30. GRB 021004: Optical Photometry at 2.5 Days
  31. GRB 021004: polarimetric observations
  32. GRB 021004: V-band Polarimetric Observations
  33. GRB021004: Update Bisei photometric data
  34. IRAM Millimeter detection of GRB 021004
  35. GRB 021004 radio observation
  36. GRB 021004: Optical Photometry at 1.5 Days
  37. GRB021004, BVRcIc field photometry
  38. GRB021004: Optical Spectroscopy
  39. GRB 021004 radio search
  40. XRF020903, BVRI field photometry
  41. XRF020903: TNG and Asiago photometry
  42. GRB 020903: Optical observations at RIKEN
  43. XRF 020903: Correction to GCN 1560
  44. XRF 020903: VRI observations
  45. XRF 020903: R band observations
  46. XRF 020903: Archival Optical Images
  47. Radio Observations of XRF 020903: The Missing Link
  48. XRF 020903: Supernova
  49. IPN triangulation of GRB020923 (two error boxes)
  50. IPN triangulation of GRB020914B
  51. IPN triangulation of GRB020911 (2 large error boxes)
  52. GRB 020305: HST/STIS observations
  53. Confirmation of IPN error box for GRB020910
  54. IPN triangulation of GRB020910
  55. IPN GCN Circulars now to be issued without restriction
  56. Single IPN error box for GRB020904
  57. XRF 020903: optical observation at Kyoto
  58. GRB020322 : HST/STIS observations
  59. XRF 020903: Optical observations
  60. IPN triangulation of GRB020904
  61. INTEGRAL GRBs added to GCN
  62. SGR1900+14 burst localized by HETE
  63. GRB020813: High-resolution optical spectroscopy
  64. GRB020812: negative optical observations
  65. GRB 020812: optical observation at Kyoto University
  66. Second epoch K band imaging of GRB 020819
  67. GRB 020813 : HST observations
  68. GRB 020812: early time optical observation at Ouda Station
  69. GRB020813: Magellan BVRI Photometry
  70. GRB 020819: Optical observations
  71. K band observation of GRB 020819
  72. GRB020813: optical and NIR observations
  73. GRB020813: Fading X-ray Afterglow Observed with Chandra
  74. GRB020813, UBVRI field calibration
  75. GRB020812: NIR observations
  76. Polarimetry of GRB020813: evidence for variability
  77. GRB020813 IRAM millimeter observations
  78. GRB020812: optical observations
  79. GRB020813: High-Resolution Optical Observations
  80. GRB 020812: optical observation at Bisei
  81. GRB020813: Early Time Magnitude
  82. Millimeter observation of GRB 020813
  83. GRB020812: optical observations
  84. GRB 020813 : KISO multiband optical observations
  85. GRB020813, optical observations
  86. IPN error box for GRB020813
  87. GRB020813, astrometric position
  88. Spectropolarimetry of GRB 020813
  89. GRB 020812 optical observation
  90. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  91. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  92. HST Imaging of the Host of GRB 011121
  93. GRB020801, optical afterglow candidate
  94. GRB020331: Late-time Optical Light Curve (re-submission)
  95. GRB020331: Late-time Optical Light Curve
  96. IPN triangulation of GRB020714
  97. IPN triangulation of GRB020715 (=GRB150702)
  98. IPN triangulation of GRB020714
  99. IPN triangulation of GRB150702
  100. GRB 020410: Discovery of Probable OT by HST

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