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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"

32544 results found.

  1. GRB 021112: R-band search
  2. IPN triangulation of GRB021108 (large error box)
  3. GRB021112 (=H2448): A Long GRB Localized by HETE
  4. GRB 021016: Optical Observations
  5. GRB021004: Near infrared spectroscopy
  6. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  7. Spectropolarimetry of GRB021004
  8. GRB021104: optical observations
  9. GRB021104: Candidate present in DSS
  10. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  11. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  12. IPN triangulation of GRB021025 (portion of annulus)
  13. IPN triangulation of GRB021027 (single large error box)
  14. GRB021004, late-time optical observations
  15. IPN triangulation of GRB021027 (two large error boxes)
  16. GRB 021023: Infrared Imaging
  17. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  18. IPN triangulation of SGR1900+14, October 22 2002
  19. GRB 021004: optical observations
  20. GRB021004: Optical Observations
  21. GRB 020813; likely host galaxy.
  22. IPN triangulation of GRB021020 (smaller error box)
  23. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  24. GRB 021008, radio observations
  25. GRB 021016, optical observations
  26. GRB 021004: VRI observations at TNG: possible break
  27. GRB021016, optical observations
  28. GRB 021008, optical observations
  29. GRB021016(=H2397): A Long GRB Localized by HETE
  30. IPN triangulation of GRB021016 (area corrected)
  31. IPN triangulation of GRB021016 (small error box)
  32. GRB021004: Optical Observations
  33. IPN triangulation of GRB021013 (single error box)
  34. GRB 021004: optical spectroscopy on Oct 11
  35. IPN triangulation of GRB021013 (two small error boxes)
  36. GRB021004: High-resolution optical spectroscopy
  37. XRF 020903: flattening of the optical light curve.
  38. GRB021004, UBVRcIc field photometry update
  39. IPN triangulation of GRB021008 (single error box)
  40. GRB021004: Optical Observations
  41. GRB 021004 submm observations
  42. IPN triangulation of GRB021008 (two small error boxes)
  43. GRB 021004: Optical/NIR Observations
  44. GRB 021004: Additional V-band Polarimetric Observations
  45. GRB021004: optical observation
  46. GRB 021004: Host Galaxy Star Formation Rate
  47. GRB 021004 submm observations
  48. GRB 021004: WC wind?
  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. XRF 020903 spectrum
  55. GRB021004: optical observations and predicted break time
  56. GRB021004: BVRc photometry
  57. GRB 021004 redshift
  58. GRB021004: restart of optical decay
  59. GRB 021004: Optical Decay
  60. GRB 021004, spectroscopic observations
  61. GRB021004: not fading anymore?
  62. GRB 021004: Optical Photometry at 2.5 Days
  63. GRB 021004: polarimetric observations
  64. GRB 021004: V-band Polarimetric Observations
  65. GRB021004: Update Bisei photometric data
  66. GRB 021004: Optical Decay
  67. GRB021004, astrometric position
  68. GRB021004, Optical Observations
  69. IRAM Millimeter detection of GRB 021004
  70. GRB 021004: Optical observations at RIKEN
  71. GRB 021004 radio observation
  72. GRB 021004: Optical Observations
  73. GRB021004: continued fading
  74. GRB 021004: Optical Photometry at 1.5 Days
  75. GRB021004, Optical Observations
  76. GRB021004, BVRcIc field photometry
  77. GRB 021004: Optical observations
  78. GRB 021004: optical counterpart
  79. GRB 021004, optical observations
  80. GRB021004: Optical Spectroscopy
  81. GRB 021004: Optical Observations
  82. GRB 021004, SPM optical observations
  83. GRB 021004, optical observations
  84. GRB 021004 radio search
  85. GRB 021004: radio observations
  86. GRB 021004: steepening of the optical decay slope
  87. GRB021004: Upper limits from recent and historical observations
  88. XRF020903, BVRI field photometry
  89. GRB021004: optical observations at Nyrola
  90. GRB021004: Absorption redshift
  91. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  92. GRB021004: optical observations at Bisei
  93. GRB 021004: Kyoto observation
  94. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  95. XRF020903: TNG and Asiago photometry
  96. GRB 020903: Optical observations at RIKEN
  97. XRF 020903: Correction to GCN 1560
  98. XRF 020903: VRI observations
  99. IPN triangulation of GRB020926 (single large error box)
  100. GRB 020903: correction to GCN 1557

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