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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"

24772 results found.

  1. GRB 021016: Optical Observations
  2. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  3. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  4. SGR1900+14 activity, November 2-4, 2002
  5. GRB021104: optical observations
  6. Detection of activity from SGR 1900+14 with the RXTE/PCA
  7. IPN triangulation of GRB021027 (single large error box)
  8. IPN triangulation of GRB021027 (two large error boxes)
  9. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  10. GRB 021004: optical observations
  11. IPN triangulation of GRB021023 (small error boc)
  12. GRB 020813; likely host galaxy.
  13. IPN triangulation of GRB021020 (smaller error box)
  14. IPN triangulation of GRB021020
  15. GRB 021008, optical observations
  16. IPN triangulation of GRB021016 (small error box)
  17. IPN triangulation of GRB021014 (large error box)
  18. IPN triangulation of GRB021013 (single error box)
  19. GRB 021004: optical spectroscopy on Oct 11
  20. IPN triangulation of GRB021013 (two small error boxes)
  21. GRB021004: High-resolution optical spectroscopy
  22. XRF 020903: flattening of the optical light curve.
  23. GRB021004, UBVRcIc field photometry update
  24. IPN triangulation of GRB021008 (single error box)
  25. GRB 021004 submm observations
  26. IPN triangulation of GRB021008 (two small error boxes)
  27. GRB021004 Chandra HETG Observations
  28. GRB 021004: Optical/NIR Observations
  29. GRB 021004: Additional V-band Polarimetric Observations
  30. GRB021004: optical observation
  31. GRB 021004: Host Galaxy Star Formation Rate
  32. GRB 021004 submm observations
  33. GRB 021004: WC wind?
  34. GRB021004: NIR and Optical observations
  35. GRB 021004: Optical observations, AUDE network
  36. GRB 021004 - VLA Radio Observations
  37. GRB 021004 - Unusual Radio-to-Submm Spectrum
  38. GRB 021004: optical spectroscopy
  39. IPN triangulation of GRB021007 (annulus)
  40. GRB021004: optical observations and predicted break time
  41. GRB021004: BVRc photometry
  42. GRB021004 radio observation
  43. HETE fluences for GRB021004
  44. GRB 021004: Optical Photometry at 2.5 Days
  45. GRB 021004: polarimetric observations
  46. GRB 021004: V-band Polarimetric Observations
  47. GRB021004: Update Bisei photometric data
  48. IRAM Millimeter detection of GRB 021004
  49. GRB 021004 radio observation
  50. GRB 021004: Optical Photometry at 1.5 Days
  51. GRB021004, BVRcIc field photometry
  52. GRB021004: Optical Spectroscopy
  53. GRB 021004 radio search
  54. XRF020903, BVRI field photometry
  55. XRF020903: TNG and Asiago photometry
  56. GRB 020903: Optical observations at RIKEN
  57. XRF 020903: Correction to GCN 1560
  58. XRF 020903: VRI observations
  59. XRF 020903: R band observations
  60. XRF 020903: Archival Optical Images
  61. Radio Observations of XRF 020903: The Missing Link
  62. XRF 020903: Supernova
  63. IPN triangulation of GRB020923 (two error boxes)
  64. IPN triangulation of GRB020914B
  65. IPN triangulation of GRB020911 (2 large error boxes)
  66. GRB 020305: HST/STIS observations
  67. Confirmation of IPN error box for GRB020910
  68. IPN triangulation of GRB020910
  69. IPN GCN Circulars now to be issued without restriction
  70. Single IPN error box for GRB020904
  71. XRF 020903: optical observation at Kyoto
  72. GRB020322 : HST/STIS observations
  73. XRF 020903: Optical observations
  74. IPN triangulation of GRB020904
  75. INTEGRAL GRBs added to GCN
  76. SGR1900+14 burst localized by HETE
  77. GRB020813: High-resolution optical spectroscopy
  78. GRB020812: negative optical observations
  79. GRB 020812: optical observation at Kyoto University
  80. Second epoch K band imaging of GRB 020819
  81. GRB 020813 : HST observations
  82. GRB 020812: early time optical observation at Ouda Station
  83. GRB020813: Magellan BVRI Photometry
  84. GRB 020819: Optical observations
  85. K band observation of GRB 020819
  86. GRB020813: optical and NIR observations
  87. GRB020813: Fading X-ray Afterglow Observed with Chandra
  88. GRB020813, UBVRI field calibration
  89. GRB020812: NIR observations
  90. Polarimetry of GRB020813: evidence for variability
  91. GRB020813 IRAM millimeter observations
  92. GRB020812: optical observations
  93. GRB020813: High-Resolution Optical Observations
  94. GRB 020812: optical observation at Bisei
  95. GRB020813: Early Time Magnitude
  96. Millimeter observation of GRB 020813
  97. GRB020812: optical observations
  98. GRB 020813 : KISO multiband optical observations
  99. GRB020813, optical observations
  100. IPN error box for GRB020813

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