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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"

35449 results found.

  1. GRB 021112: Afterglow or Variable Star?
  2. GRB021113: optical observations at Bisei
  3. GRB 021113: Evidence for a Dark Optical Afterglow
  4. GRB 021112, Radio Observations
  5. GRB021112, BVRI field photometry
  6. GRB 021112: Variable Source in R-band search
  7. GRB021112: Optical Observations
  8. GRB021113: Kiso Observations
  9. IPN triangulation of GRB021109 (portion of annulus)
  10. IPN triangulation of GRB021113 (=H2449; annulus)
  11. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  12. GRB 021113: Optical observations
  13. GRB 021112: RAPTOR Observations
  14. GRB 021113: Optical Observations
  15. GRB 021113: Optical Observations
  16. GRB021113 (=H2449): A Long GRB Localized by HETE
  17. GRB 021112: Optical Observations
  18. GRB 021112: R-band search
  19. IPN triangulation of GRB021108 (large error box)
  20. GRB021112 (=H2448): A Long GRB Localized by HETE
  21. GRB 021016: Optical Observations
  22. IPN triangulation of GRB021109 (annulus)
  23. IPN triangulation of GRB021108 (annulus)
  24. IPN triangulation of GRB021104 (annulus)
  25. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  26. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  27. SGR1900+14 activity, November 2-4, 2002
  28. GRB021104: Candidate present in DSS
  29. IPN triangulation of GRB021102 (annulus)
  30. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  31. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  32. IPN triangulation of GRB021025 (portion of annulus)
  33. IPN triangulation of GRB021027 (single large error box)
  34. GRB021004, late-time optical observations
  35. IPN triangulation of GRB021027 (two large error boxes)
  36. GRB 021023: Infrared Imaging
  37. IPN triangulation of GRB021027 (annulus)
  38. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  39. IPN triangulation of GRB021025 (annulus)
  40. IPN triangulation of SGR1900+14, October 22 2002
  41. GRB 021004: optical observations
  42. IPN triangulation of GRB021023 (small error boc)
  43. GRB 020813; likely host galaxy.
  44. IPN triangulation of GRB021020 (smaller error box)
  45. IPN triangulation of GRB021020
  46. GRB 021008, radio observations
  47. GRB 021016, optical observations
  48. GRB 021004: VRI observations at TNG: possible break
  49. GRB021016, optical observations
  50. SGR1900+14: burst on October 10 2002
  51. GRB 021008, optical observations
  52. GRB021016(=H2397): A Long GRB Localized by HETE
  53. IPN triangulation of GRB021016 (small error box)
  54. IPN triangulation of GRB021014 (large error box)
  55. IPN triangulation of GRB021013 (single error box)
  56. GRB 021004: optical spectroscopy on Oct 11
  57. IPN triangulation of GRB021013 (two small error boxes)
  58. GRB021004: High-resolution optical spectroscopy
  59. IPN triangulation of GRB021013 (annulus)
  60. GRB021004, UBVRcIc field photometry update
  61. IPN triangulation of GRB021008 (single error box)
  62. GRB 021004 submm observations
  63. IPN triangulation of GRB021008B (annulus)
  64. IPN triangulation of GRB021008 (two small error boxes)
  65. GRB 021004: Optical/NIR Observations
  66. GRB 021004: Additional V-band Polarimetric Observations
  67. GRB021004: optical observation
  68. GRB 021004: Host Galaxy Star Formation Rate
  69. GRB 021004 submm observations
  70. GRB 021004: WC wind?
  71. IPN triangulation of GRB021008
  72. GRB 021004: Optical measurement at OHP
  73. GRB 021004: Optical observations, AUDE network
  74. GRB 021004 - VLA Radio Observations
  75. GRB 021004 - Unusual Radio-to-Submm Spectrum
  76. GRB 021004: optical spectroscopy
  77. IPN triangulation of GRB021007 (annulus)
  78. GRB 021004: HST/STIS spectroscopic observations
  79. GRB021004: optical observations and predicted break time
  80. GRB 021004 redshift
  81. GRB 021004: Optical Decay
  82. GRB 021004 continued IR fading
  83. HETE fluences for GRB021004
  84. GRB 021004, spectroscopic observations
  85. GRB021004: not fading anymore?
  86. GRB 021004: Optical Photometry at 2.5 Days
  87. GRB 021004: polarimetric observations
  88. GRB 021004: V-band Polarimetric Observations
  89. GRB 021004: Optical Decay
  90. GRB021004, astrometric position
  91. GRB021004, Optical Observations
  92. IRAM Millimeter detection of GRB 021004
  93. GRB 021004: Optical observations at RIKEN
  94. GRB 021004 radio observation
  95. GRB 021004: Optical Observations
  96. GRB021004: continued fading
  97. GRB 021004: Optical Photometry at 1.5 Days
  98. GRB021004, Optical Observations
  99. GRB021004, BVRcIc field photometry
  100. GRB 021004: Optical observations

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