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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"

36030 results found.

  1. GRB021004: Near infrared spectroscopy
  2. IPN triangulation of GRB021104 (annulus)
  3. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  4. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  5. SGR1900+14 activity, November 2-4, 2002
  6. Spectropolarimetry of GRB021004
  7. GRB021104: Candidate present in DSS
  8. IPN triangulation of GRB021102 (annulus)
  9. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  10. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  11. IPN triangulation of GRB021025 (portion of annulus)
  12. IPN triangulation of GRB021027 (single large error box)
  13. GRB021004, late-time optical observations
  14. IPN triangulation of GRB021027 (two large error boxes)
  15. GRB 021023: Infrared Imaging
  16. IPN triangulation of GRB021027 (annulus)
  17. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  18. IPN triangulation of GRB021025 (annulus)
  19. IPN triangulation of SGR1900+14, October 22 2002
  20. GRB 021004: optical observations
  21. IPN triangulation of GRB021023 (small error boc)
  22. GRB 020813; likely host galaxy.
  23. IPN triangulation of GRB021020 (smaller error box)
  24. IPN triangulation of GRB021020
  25. GRB 021008, radio observations
  26. GRB 021016, optical observations
  27. GRB 021004: VRI observations at TNG: possible break
  28. GRB021016, optical observations
  29. SGR1900+14: burst on October 10 2002
  30. GRB 021008, optical observations
  31. GRB021016(=H2397): A Long GRB Localized by HETE
  32. IPN triangulation of GRB021016 (small error box)
  33. IPN triangulation of GRB021014 (large error box)
  34. IPN triangulation of GRB021013 (single error box)
  35. GRB 021004: optical spectroscopy on Oct 11
  36. IPN triangulation of GRB021013 (two small error boxes)
  37. GRB021004: High-resolution optical spectroscopy
  38. IPN triangulation of GRB021013 (annulus)
  39. GRB021004, UBVRcIc field photometry update
  40. IPN triangulation of GRB021008 (single error box)
  41. GRB 021004 submm observations
  42. IPN triangulation of GRB021008B (annulus)
  43. IPN triangulation of GRB021008 (two small error boxes)
  44. GRB 021004: Optical/NIR Observations
  45. GRB 021004: Additional V-band Polarimetric Observations
  46. GRB021004: optical observation
  47. GRB 021004: Host Galaxy Star Formation Rate
  48. GRB 021004 submm observations
  49. GRB 021004: WC wind?
  50. IPN triangulation of GRB021008
  51. GRB 021004: Optical measurement at OHP
  52. GRB 021004: Optical observations, AUDE network
  53. GRB 021004 - VLA Radio Observations
  54. GRB 021004 - Unusual Radio-to-Submm Spectrum
  55. GRB 021004: optical spectroscopy
  56. IPN triangulation of GRB021007 (annulus)
  57. GRB 021004: HST/STIS spectroscopic observations
  58. GRB021004: optical observations and predicted break time
  59. GRB 021004 redshift
  60. GRB 021004: Optical Decay
  61. GRB 021004 continued IR fading
  62. HETE fluences for GRB021004
  63. GRB 021004, spectroscopic observations
  64. GRB021004: not fading anymore?
  65. GRB 021004: Optical Photometry at 2.5 Days
  66. GRB 021004: polarimetric observations
  67. GRB 021004: V-band Polarimetric Observations
  68. GRB 021004: Optical Decay
  69. GRB021004, astrometric position
  70. GRB021004, Optical Observations
  71. IRAM Millimeter detection of GRB 021004
  72. GRB 021004: Optical observations at RIKEN
  73. GRB 021004 radio observation
  74. GRB 021004: Optical Observations
  75. GRB021004: continued fading
  76. GRB 021004: Optical Photometry at 1.5 Days
  77. GRB021004, Optical Observations
  78. GRB021004, BVRcIc field photometry
  79. GRB 021004: Optical observations
  80. GRB 021004: optical counterpart
  81. GRB 021004, optical observations
  82. GRB021004: Optical Spectroscopy
  83. GRB 021004: Optical Observations
  84. GRB 021004, SPM optical observations
  85. GRB 021004, optical observations
  86. GRB 021004 radio search
  87. GRB 021004: radio observations
  88. GRB 021004: steepening of the optical decay slope
  89. GRB021004: Upper limits from recent and historical observations
  90. XRF020903, BVRI field photometry
  91. GRB021004: optical observations at Nyrola
  92. GRB021004: Absorption redshift
  93. GRB 021004: Kyoto observation
  94. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  95. GRB021004: Optical Afterglow
  96. GRB 020903: Optical observations at RIKEN
  97. IPN triangulation of GRB020926 (single large error box)
  98. GRB 020903: correction to GCN 1557
  99. XRF 020903: R band observations
  100. Radio Observations of XRF 020903: The Missing Link

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