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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"

24664 results found.

  1. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  2. GRB 021004: optical observations
  3. IPN triangulation of GRB021023 (small error boc)
  4. GRB 020813; likely host galaxy.
  5. IPN triangulation of GRB021020 (smaller error box)
  6. IPN triangulation of GRB021020
  7. GRB 021008, optical observations
  8. IPN triangulation of GRB021016 (small error box)
  9. IPN triangulation of GRB021014 (large error box)
  10. IPN triangulation of GRB021013 (single error box)
  11. GRB 021004: optical spectroscopy on Oct 11
  12. IPN triangulation of GRB021013 (two small error boxes)
  13. GRB021004: High-resolution optical spectroscopy
  14. XRF 020903: flattening of the optical light curve.
  15. GRB021004, UBVRcIc field photometry update
  16. IPN triangulation of GRB021008 (single error box)
  17. GRB 021004 submm observations
  18. IPN triangulation of GRB021008 (two small error boxes)
  19. GRB021004 Chandra HETG Observations
  20. GRB 021004: Optical/NIR Observations
  21. GRB 021004: Additional V-band Polarimetric Observations
  22. GRB021004: optical observation
  23. GRB 021004: Host Galaxy Star Formation Rate
  24. GRB 021004 submm observations
  25. GRB 021004: WC wind?
  26. GRB021004: NIR and Optical observations
  27. GRB 021004: Optical observations, AUDE network
  28. GRB 021004 - VLA Radio Observations
  29. GRB 021004 - Unusual Radio-to-Submm Spectrum
  30. GRB 021004: optical spectroscopy
  31. IPN triangulation of GRB021007 (annulus)
  32. GRB021004: optical observations and predicted break time
  33. GRB021004: BVRc photometry
  34. GRB021004 radio observation
  35. HETE fluences for GRB021004
  36. GRB 021004: Optical Photometry at 2.5 Days
  37. GRB 021004: polarimetric observations
  38. GRB 021004: V-band Polarimetric Observations
  39. GRB021004: Update Bisei photometric data
  40. IRAM Millimeter detection of GRB 021004
  41. GRB 021004 radio observation
  42. GRB 021004: Optical Photometry at 1.5 Days
  43. GRB021004, BVRcIc field photometry
  44. GRB021004: Optical Spectroscopy
  45. GRB 021004 radio search
  46. XRF020903, BVRI field photometry
  47. XRF020903: TNG and Asiago photometry
  48. GRB 020903: Optical observations at RIKEN
  49. XRF 020903: Correction to GCN 1560
  50. XRF 020903: VRI observations
  51. XRF 020903: R band observations
  52. XRF 020903: Archival Optical Images
  53. Radio Observations of XRF 020903: The Missing Link
  54. XRF 020903: Supernova
  55. IPN triangulation of GRB020923 (two error boxes)
  56. IPN triangulation of GRB020914B
  57. IPN triangulation of GRB020911 (2 large error boxes)
  58. GRB 020305: HST/STIS observations
  59. Confirmation of IPN error box for GRB020910
  60. IPN triangulation of GRB020910
  61. IPN GCN Circulars now to be issued without restriction
  62. Single IPN error box for GRB020904
  63. XRF 020903: optical observation at Kyoto
  64. GRB020322 : HST/STIS observations
  65. XRF 020903: Optical observations
  66. IPN triangulation of GRB020904
  67. INTEGRAL GRBs added to GCN
  68. SGR1900+14 burst localized by HETE
  69. GRB020813: High-resolution optical spectroscopy
  70. GRB020812: negative optical observations
  71. GRB 020812: optical observation at Kyoto University
  72. Second epoch K band imaging of GRB 020819
  73. GRB 020813 : HST observations
  74. GRB 020812: early time optical observation at Ouda Station
  75. GRB020813: Magellan BVRI Photometry
  76. GRB 020819: Optical observations
  77. K band observation of GRB 020819
  78. GRB020813: optical and NIR observations
  79. GRB020813: Fading X-ray Afterglow Observed with Chandra
  80. GRB020813, UBVRI field calibration
  81. GRB020812: NIR observations
  82. Polarimetry of GRB020813: evidence for variability
  83. GRB020813 IRAM millimeter observations
  84. GRB020812: optical observations
  85. GRB020813: High-Resolution Optical Observations
  86. GRB 020812: optical observation at Bisei
  87. GRB020813: Early Time Magnitude
  88. Millimeter observation of GRB 020813
  89. GRB020812: optical observations
  90. GRB 020813 : KISO multiband optical observations
  91. GRB020813, optical observations
  92. IPN error box for GRB020813
  93. GRB020813, astrometric position
  94. Spectropolarimetry of GRB 020813
  95. GRB 020812 optical observation
  96. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  97. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  98. HST Imaging of the Host of GRB 011121
  99. GRB020801, optical afterglow candidate
  100. GRB020331: Late-time Optical Light Curve (re-submission)

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