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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"

28049 results found.

  1. IPN triangulation of GRB021008 (single error box)
  2. GRB 021004 submm observations
  3. IPN triangulation of GRB021008 (two small error boxes)
  4. GRB021004 Chandra HETG Observations
  5. GRB 021004: Optical/NIR Observations
  6. GRB 021004: Additional V-band Polarimetric Observations
  7. GRB021004: optical observation
  8. GRB 021004: Host Galaxy Star Formation Rate
  9. GRB 021004 submm observations
  10. GRB 021004: WC wind?
  11. GRB021004: NIR and Optical observations
  12. GRB 021004: Optical observations, AUDE network
  13. GRB 021004 - VLA Radio Observations
  14. GRB 021004 - Unusual Radio-to-Submm Spectrum
  15. GRB 021004: optical spectroscopy
  16. IPN triangulation of GRB021007 (annulus)
  17. GRB021004: optical observations and predicted break time
  18. GRB021004: BVRc photometry
  19. GRB021004 radio observation
  20. HETE fluences for GRB021004
  21. GRB 021004: Optical Photometry at 2.5 Days
  22. GRB 021004: polarimetric observations
  23. GRB 021004: V-band Polarimetric Observations
  24. GRB021004: Update Bisei photometric data
  25. IRAM Millimeter detection of GRB 021004
  26. GRB 021004 radio observation
  27. GRB 021004: Optical Photometry at 1.5 Days
  28. GRB021004, BVRcIc field photometry
  29. GRB021004: Optical Spectroscopy
  30. GRB 021004 radio search
  31. XRF020903, BVRI field photometry
  32. XRF020903: TNG and Asiago photometry
  33. GRB 020903: Optical observations at RIKEN
  34. XRF 020903: Correction to GCN 1560
  35. XRF 020903: VRI observations
  36. XRF 020903: R band observations
  37. XRF 020903: Archival Optical Images
  38. Radio Observations of XRF 020903: The Missing Link
  39. XRF 020903: Supernova
  40. IPN triangulation of GRB020923 (two error boxes)
  41. IPN triangulation of GRB020914B
  42. IPN triangulation of GRB020911 (2 large error boxes)
  43. GRB 020305: HST/STIS observations
  44. Confirmation of IPN error box for GRB020910
  45. IPN triangulation of GRB020910
  46. IPN GCN Circulars now to be issued without restriction
  47. Single IPN error box for GRB020904
  48. XRF 020903: optical observation at Kyoto
  49. GRB020322 : HST/STIS observations
  50. XRF 020903: Optical observations
  51. IPN triangulation of GRB020904
  52. INTEGRAL GRBs added to GCN
  53. SGR1900+14 burst localized by HETE
  54. GRB020813: High-resolution optical spectroscopy
  55. GRB020812: negative optical observations
  56. GRB 020812: optical observation at Kyoto University
  57. Second epoch K band imaging of GRB 020819
  58. GRB 020813 : HST observations
  59. GRB 020812: early time optical observation at Ouda Station
  60. GRB020813: Magellan BVRI Photometry
  61. GRB 020819: Optical observations
  62. K band observation of GRB 020819
  63. GRB020813: optical and NIR observations
  64. GRB020813: Fading X-ray Afterglow Observed with Chandra
  65. GRB020813, UBVRI field calibration
  66. GRB020812: NIR observations
  67. Polarimetry of GRB020813: evidence for variability
  68. GRB020813 IRAM millimeter observations
  69. GRB020812: optical observations
  70. GRB020813: High-Resolution Optical Observations
  71. GRB 020812: optical observation at Bisei
  72. GRB020813: Early Time Magnitude
  73. Millimeter observation of GRB 020813
  74. GRB020812: optical observations
  75. GRB 020813 : KISO multiband optical observations
  76. GRB020813, optical observations
  77. IPN error box for GRB020813
  78. GRB020813, astrometric position
  79. Spectropolarimetry of GRB 020813
  80. GRB 020812 optical observation
  81. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  82. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  83. HST Imaging of the Host of GRB 011121
  84. GRB020801, optical afterglow candidate
  85. GRB020331: Late-time Optical Light Curve (re-submission)
  86. GRB020331: Late-time Optical Light Curve
  87. IPN triangulation of GRB020714
  88. IPN triangulation of GRB020715 (=GRB150702)
  89. IPN triangulation of GRB020714
  90. IPN triangulation of GRB150702
  91. GRB 020410: Discovery of Probable OT by HST
  92. GRB 020124, HST observations of the fading afterglow
  93. IPN triangulation of GRB020708
  94. IPN triangulation of GRB020708
  95. Correction to IPN error box for GRB020706
  96. IPN triangulation of GRB020706
  97. GRB 020705: Optical observations
  98. GRB 020625, optical observations
  99. GRB 020625: Optical observations
  100. GRB 020531: optical photometry of Chandra sources

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