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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"

24670 results found.

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

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