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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"

25848 results found.

  1. GRB 021004 submm observations
  2. IPN triangulation of GRB021008 (two small error boxes)
  3. GRB021004 Chandra HETG Observations
  4. GRB 021004: Optical/NIR Observations
  5. GRB 021004: Additional V-band Polarimetric Observations
  6. GRB021004: optical observation
  7. GRB 021004: Host Galaxy Star Formation Rate
  8. GRB 021004 submm observations
  9. GRB 021004: WC wind?
  10. GRB021004: NIR and Optical observations
  11. GRB 021004: Optical observations, AUDE network
  12. GRB 021004 - VLA Radio Observations
  13. GRB 021004 - Unusual Radio-to-Submm Spectrum
  14. GRB 021004: optical spectroscopy
  15. IPN triangulation of GRB021007 (annulus)
  16. GRB021004: optical observations and predicted break time
  17. GRB021004: BVRc photometry
  18. GRB021004 radio observation
  19. HETE fluences for GRB021004
  20. GRB 021004: Optical Photometry at 2.5 Days
  21. GRB 021004: polarimetric observations
  22. GRB 021004: V-band Polarimetric Observations
  23. GRB021004: Update Bisei photometric data
  24. IRAM Millimeter detection of GRB 021004
  25. GRB 021004 radio observation
  26. GRB 021004: Optical Photometry at 1.5 Days
  27. GRB021004, BVRcIc field photometry
  28. GRB021004: Optical Spectroscopy
  29. GRB 021004 radio search
  30. XRF020903, BVRI field photometry
  31. XRF020903: TNG and Asiago photometry
  32. GRB 020903: Optical observations at RIKEN
  33. XRF 020903: Correction to GCN 1560
  34. XRF 020903: VRI observations
  35. XRF 020903: R band observations
  36. XRF 020903: Archival Optical Images
  37. Radio Observations of XRF 020903: The Missing Link
  38. XRF 020903: Supernova
  39. IPN triangulation of GRB020923 (two error boxes)
  40. IPN triangulation of GRB020914B
  41. IPN triangulation of GRB020911 (2 large error boxes)
  42. GRB 020305: HST/STIS observations
  43. Confirmation of IPN error box for GRB020910
  44. IPN triangulation of GRB020910
  45. IPN GCN Circulars now to be issued without restriction
  46. Single IPN error box for GRB020904
  47. XRF 020903: optical observation at Kyoto
  48. GRB020322 : HST/STIS observations
  49. XRF 020903: Optical observations
  50. IPN triangulation of GRB020904
  51. INTEGRAL GRBs added to GCN
  52. SGR1900+14 burst localized by HETE
  53. GRB020813: High-resolution optical spectroscopy
  54. GRB020812: negative optical observations
  55. GRB 020812: optical observation at Kyoto University
  56. Second epoch K band imaging of GRB 020819
  57. GRB 020813 : HST observations
  58. GRB 020812: early time optical observation at Ouda Station
  59. GRB020813: Magellan BVRI Photometry
  60. GRB 020819: Optical observations
  61. K band observation of GRB 020819
  62. GRB020813: optical and NIR observations
  63. GRB020813: Fading X-ray Afterglow Observed with Chandra
  64. GRB020813, UBVRI field calibration
  65. GRB020812: NIR observations
  66. Polarimetry of GRB020813: evidence for variability
  67. GRB020813 IRAM millimeter observations
  68. GRB020812: optical observations
  69. GRB020813: High-Resolution Optical Observations
  70. GRB 020812: optical observation at Bisei
  71. GRB020813: Early Time Magnitude
  72. Millimeter observation of GRB 020813
  73. GRB020812: optical observations
  74. GRB 020813 : KISO multiband optical observations
  75. GRB020813, optical observations
  76. IPN error box for GRB020813
  77. GRB020813, astrometric position
  78. Spectropolarimetry of GRB 020813
  79. GRB 020812 optical observation
  80. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  81. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  82. HST Imaging of the Host of GRB 011121
  83. GRB020801, optical afterglow candidate
  84. GRB020331: Late-time Optical Light Curve (re-submission)
  85. GRB020331: Late-time Optical Light Curve
  86. IPN triangulation of GRB020714
  87. IPN triangulation of GRB020715 (=GRB150702)
  88. IPN triangulation of GRB020714
  89. IPN triangulation of GRB150702
  90. GRB 020410: Discovery of Probable OT by HST
  91. GRB 020124, HST observations of the fading afterglow
  92. IPN triangulation of GRB020708
  93. IPN triangulation of GRB020708
  94. Correction to IPN error box for GRB020706
  95. IPN triangulation of GRB020706
  96. GRB 020705: Optical observations
  97. GRB 020625, optical observations
  98. GRB 020625: Optical observations
  99. GRB 020531: optical photometry of Chandra sources
  100. GRB020625 (=H2081): A Long Burst Localized by HETE

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