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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"

42250 results found.

  1. GRB 021004 submm observations
  2. GRB 021004: WC wind?
  3. IPN triangulation of GRB021008
  4. GRB021004: NIR and Optical observations
  5. GRB 021004: Optical measurement at OHP
  6. GRB 021004: Optical observations, AUDE network
  7. GRB 021004 - VLA Radio Observations
  8. GRB 021004 - Unusual Radio-to-Submm Spectrum
  9. GRB 021004: optical spectroscopy
  10. IPN triangulation of GRB021007 (annulus)
  11. XRF 020903 spectrum
  12. GRB 021004: HST/STIS spectroscopic observations
  13. GRB021004: optical observations and predicted break time
  14. GRB021004: BVRc photometry
  15. GRB 021004 redshift
  16. GRB021004 radio observation
  17. GRB021004: restart of optical decay
  18. GRB 021004: Optical Decay
  19. GRB 021004 continued IR fading
  20. HETE fluences for GRB021004
  21. GRB 021004, spectroscopic observations
  22. GRB021004: not fading anymore?
  23. GRB 021004: Optical Photometry at 2.5 Days
  24. GRB 021004: polarimetric observations
  25. GRB 021004: V-band Polarimetric Observations
  26. GRB 021004: Optical Decay
  27. GRB021004, astrometric position
  28. GRB021004, Optical Observations
  29. IRAM Millimeter detection of GRB 021004
  30. GRB 021004: Optical observations at RIKEN
  31. GRB 021004 radio observation
  32. GRB 021004: Optical Observations
  33. GRB021004: continued fading
  34. GRB 021004: Optical Photometry at 1.5 Days
  35. GRB021004, Optical Observations
  36. GRB021004, BVRcIc field photometry
  37. GRB 021004: Optical observations
  38. GRB 021004: optical counterpart
  39. GRB 021004, optical observations
  40. GRB021004: Optical Spectroscopy
  41. GRB 021004: Optical Observations
  42. GRB 021004, SPM optical observations
  43. GRB 021004, optical observations
  44. GRB 021004 radio search
  45. GRB 021004: radio observations
  46. GRB 021004: steepening of the optical decay slope
  47. GRB021004: Upper limits from recent and historical observations
  48. XRF020903, BVRI field photometry
  49. GRB021004: optical observations at Nyrola
  50. GRB021004: Absorption redshift
  51. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  52. GRB021004: optical observations at Bisei
  53. GRB 021004: Kyoto observation
  54. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  55. GRB021004: Optical Afterglow
  56. XRF020903: TNG and Asiago photometry
  57. GRB 020903: Optical observations at RIKEN
  58. XRF 020903: Correction to GCN 1560
  59. XRF 020903: VRI observations
  60. IPN triangulation of GRB020926 (single large error box)
  61. XRF 020903: R band observations
  62. XRF 020903: Archival Optical Images
  63. Radio Observations of XRF 020903: The Missing Link
  64. XRF 020903: Supernova
  65. IPN triangulation of GRB020926 (two large error boxes)
  66. GRB020924 (ecliptic latitude-only localization)
  67. IPN annulus for GRB020923
  68. IPN triangulation of GRB020914B
  69. Improved IPN position for GRB020918 (two large error boxes)
  70. IPN annulus for GRB020914B
  71. IPN triangulation of GRB020911 (2 large error boxes)
  72. IPN triangulation of GRB020914 - clarification and additional information
  73. IPN triangulation of GRB020914
  74. GRB 020305: HST/STIS observations
  75. IPN GCN Circulars now to be issued without restriction
  76. XRF 020903: optical observation at Kyoto
  77. GRB020322 : HST/STIS observations
  78. XRF 020903: Optical observations
  79. IPN triangulation of GRB020904
  80. XRF 020903: Optical observations
  81. IPN detection of a burst from SGR1900+14
  82. XRF 020903, optical observations
  83. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  84. INTEGRAL GRBs added to GCN
  85. GRB020813: optical observation
  86. GRB020812: optical observation
  87. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  88. SGR1900+14 burst localized by HETE
  89. GRB020813: High-resolution optical spectroscopy
  90. GRB020819: optical observations at Bisei
  91. GRB020812: negative optical observations
  92. GRB 020812: optical observation at Kyoto University
  93. Second epoch K band imaging of GRB 020819
  94. GRB020813, Baade 6.5m data now available
  95. GRB 020813 : HST observations
  96. Confirming no variability for GRB02081
  97. GRB020819 : Optical observations at KISO
  98. GRB 020812: early time optical observation at Ouda Station
  99. GRB020813: VRI Decay Slopes
  100. GRB020813: Magellan BVRI Photometry

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