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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"

45466 results found.

  1. GRB 021112: Optical Observations
  2. GRB 021112: R-band search
  3. IPN triangulation of GRB021108 (large error box)
  4. GRB021112 (=H2448): A Long GRB Localized by HETE
  5. GRB 021016: Optical Observations
  6. IPN triangulation of GRB021109 (annulus)
  7. IPN triangulation of GRB021108 (annulus)
  8. GRB021004: Near infrared spectroscopy
  9. GRB021104: Optical Observations
  10. IPN triangulation of GRB021104 (annulus)
  11. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  12. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  13. SGR1900+14 activity, November 2-4, 2002
  14. Spectropolarimetry of GRB021004
  15. GRB021104: Optical observations
  16. GRB021104: optical observations
  17. GRB021104: Candidate present in DSS
  18. GRB021104: possible optical afterglow
  19. IPN triangulation of GRB021102 (annulus)
  20. Detection of activity from SGR 1900+14 with the RXTE/PCA
  21. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  22. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  23. IPN triangulation of GRB021025 (portion of annulus)
  24. IPN triangulation of GRB021027 (single large error box)
  25. GRB021004, late-time optical observations
  26. IPN triangulation of GRB021027 (two large error boxes)
  27. IPN triangulation of GRB021027 (annulus)
  28. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  29. IPN triangulation of GRB021025 (annulus)
  30. IPN triangulation of SGR1900+14, October 22 2002
  31. GRB 021004: optical observations
  32. IPN triangulation of GRB021023 (small error boc)
  33. GRB021004: Optical Observations
  34. GRB 020813; likely host galaxy.
  35. IPN triangulation of GRB021020 (smaller error box)
  36. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  37. IPN triangulation of GRB021020
  38. GRB 021008, radio observations
  39. GRB 021016, optical observations
  40. GRB 021004: VRI observations at TNG: possible break
  41. GRB021016, optical observations
  42. SGR1900+14: burst on October 10 2002
  43. GRB 021008, optical observations
  44. GRB021016(=H2397): A Long GRB Localized by HETE
  45. IPN triangulation of GRB021016 (area corrected)
  46. IPN triangulation of GRB021016 (small error box)
  47. GRB021004: Optical Observations
  48. IPN triangulation of GRB021014 (large error box)
  49. IPN triangulation of GRB021013 (single error box)
  50. GRB 021004: optical spectroscopy on Oct 11
  51. IPN triangulation of GRB021013 (two small error boxes)
  52. GRB021004: High-resolution optical spectroscopy
  53. IPN triangulation of GRB021013 (annulus)
  54. XRF 020903: flattening of the optical light curve.
  55. GRB021004, UBVRcIc field photometry update
  56. IPN triangulation of GRB021008 (single error box)
  57. GRB021004: Optical Observations
  58. GRB 021004 submm observations
  59. IPN triangulation of GRB021008B (annulus)
  60. IPN triangulation of GRB021008 (two small error boxes)
  61. GRB021004 Chandra HETG Observations
  62. GRB 021004: Optical/NIR Observations
  63. GRB 021004: Additional V-band Polarimetric Observations
  64. GRB021004: optical observation
  65. GRB 021004: Host Galaxy Star Formation Rate
  66. GRB 021004 submm observations
  67. GRB 021004: WC wind?
  68. IPN triangulation of GRB021008
  69. GRB021004: NIR and Optical observations
  70. GRB 021004: Optical measurement at OHP
  71. GRB 021004: Optical observations, AUDE network
  72. GRB 021004 - VLA Radio Observations
  73. GRB 021004 - Unusual Radio-to-Submm Spectrum
  74. GRB 021004: optical spectroscopy
  75. IPN triangulation of GRB021007 (annulus)
  76. XRF 020903 spectrum
  77. GRB 021004: HST/STIS spectroscopic observations
  78. GRB021004: optical observations and predicted break time
  79. GRB021004: BVRc photometry
  80. GRB 021004 redshift
  81. GRB021004 radio observation
  82. GRB021004: restart of optical decay
  83. GRB 021004: Optical Decay
  84. GRB 021004 continued IR fading
  85. HETE fluences for GRB021004
  86. GRB 021004, spectroscopic observations
  87. GRB021004: not fading anymore?
  88. GRB 021004: Optical Photometry at 2.5 Days
  89. GRB 021004: polarimetric observations
  90. GRB 021004: V-band Polarimetric Observations
  91. GRB021004: Update Bisei photometric data
  92. GRB 021004: Optical Decay
  93. GRB021004, astrometric position
  94. GRB021004, Optical Observations
  95. IRAM Millimeter detection of GRB 021004
  96. GRB 021004: Optical observations at RIKEN
  97. GRB 021004 radio observation
  98. GRB 021004: Optical Observations
  99. GRB021004: continued fading
  100. GRB 021004: Optical Photometry at 1.5 Days

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