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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"

45666 results found.

  1. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  2. IPN triangulation of GRB021025 (portion of annulus)
  3. IPN triangulation of GRB021027 (single large error box)
  4. GRB021004, late-time optical observations
  5. IPN triangulation of GRB021027 (two large error boxes)
  6. GRB 021023: Infrared Imaging
  7. IPN triangulation of GRB021027 (annulus)
  8. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  9. IPN triangulation of GRB021025 (annulus)
  10. IPN triangulation of SGR1900+14, October 22 2002
  11. GRB 021004: optical observations
  12. IPN triangulation of GRB021023 (small error boc)
  13. GRB021004: Optical Observations
  14. GRB 020813; likely host galaxy.
  15. IPN triangulation of GRB021020 (smaller error box)
  16. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  17. IPN triangulation of GRB021020
  18. GRB 021008, radio observations
  19. GRB 021016, optical observations
  20. GRB 021004: VRI observations at TNG: possible break
  21. GRB021016, optical observations
  22. SGR1900+14: burst on October 10 2002
  23. GRB 021008, optical observations
  24. GRB021016(=H2397): A Long GRB Localized by HETE
  25. IPN triangulation of GRB021016 (area corrected)
  26. IPN triangulation of GRB021016 (small error box)
  27. GRB021004: Optical Observations
  28. IPN triangulation of GRB021014 (large error box)
  29. IPN triangulation of GRB021013 (single error box)
  30. GRB 021004: optical spectroscopy on Oct 11
  31. IPN triangulation of GRB021013 (two small error boxes)
  32. GRB021004: High-resolution optical spectroscopy
  33. IPN triangulation of GRB021013 (annulus)
  34. XRF 020903: flattening of the optical light curve.
  35. GRB021004, UBVRcIc field photometry update
  36. IPN triangulation of GRB021008 (single error box)
  37. GRB021004: Optical Observations
  38. GRB 021004 submm observations
  39. IPN triangulation of GRB021008B (annulus)
  40. IPN triangulation of GRB021008 (two small error boxes)
  41. GRB021004 Chandra HETG Observations
  42. GRB 021004: Optical/NIR Observations
  43. GRB 021004: Additional V-band Polarimetric Observations
  44. GRB021004: optical observation
  45. GRB 021004: Host Galaxy Star Formation Rate
  46. GRB 021004 submm observations
  47. GRB 021004: WC wind?
  48. IPN triangulation of GRB021008
  49. GRB021004: NIR and Optical observations
  50. GRB 021004: Optical measurement at OHP
  51. GRB 021004: Optical observations, AUDE network
  52. GRB 021004 - VLA Radio Observations
  53. GRB 021004 - Unusual Radio-to-Submm Spectrum
  54. GRB 021004: optical spectroscopy
  55. IPN triangulation of GRB021007 (annulus)
  56. XRF 020903 spectrum
  57. GRB 021004: HST/STIS spectroscopic observations
  58. GRB021004: optical observations and predicted break time
  59. GRB021004: BVRc photometry
  60. GRB 021004 redshift
  61. GRB021004 radio observation
  62. GRB021004: restart of optical decay
  63. GRB 021004: Optical Decay
  64. GRB 021004 continued IR fading
  65. HETE fluences for GRB021004
  66. GRB 021004, spectroscopic observations
  67. GRB021004: not fading anymore?
  68. GRB 021004: Optical Photometry at 2.5 Days
  69. GRB 021004: polarimetric observations
  70. GRB 021004: V-band Polarimetric Observations
  71. GRB021004: Update Bisei photometric data
  72. GRB 021004: Optical Decay
  73. GRB021004, astrometric position
  74. GRB021004, Optical Observations
  75. IRAM Millimeter detection of GRB 021004
  76. GRB 021004: Optical observations at RIKEN
  77. GRB 021004 radio observation
  78. GRB 021004: Optical Observations
  79. GRB021004: continued fading
  80. GRB 021004: Optical Photometry at 1.5 Days
  81. GRB021004, Optical Observations
  82. GRB021004, BVRcIc field photometry
  83. GRB 021004: Optical observations
  84. GRB 021004: optical counterpart
  85. GRB 021004, optical observations
  86. GRB021004: Optical Spectroscopy
  87. GRB 021004: Optical Observations
  88. GRB 021004, SPM optical observations
  89. GRB 021004, optical observations
  90. GRB 021004 radio search
  91. GRB 021004: radio observations
  92. GRB 021004: steepening of the optical decay slope
  93. GRB021004: Upper limits from recent and historical observations
  94. XRF020903, BVRI field photometry
  95. GRB021004: optical observations at Nyrola
  96. GRB021004: Absorption redshift
  97. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  98. GRB021004: optical observations at Bisei
  99. GRB 021004: Kyoto observation
  100. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time

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