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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"

27402 results found.

  1. SUB-MM SEARCH FOR GRB 021211
  2. Chandra observation of the IPN error box of GRB021201 (short/hard)
  3. GRB 021211, R- and I-band observations
  4. GRB021211 - Upper limits from recent and historical observations
  5. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  6. IPN triangulation of GRB021206 (small error box)
  7. IPN triangulation of GRB021205 (large error box)
  8. GRB021201, BVRcIc field photometry
  9. GRB 021201: BOOTES simultaneous optical observations
  10. IPN triangulation of GRB021201 (short/hard burst, small error box)
  11. GRB021004, late time optical observations
  12. GRB021004 Chandra Observation
  13. IPN detection of continued SGR1900+14 activity
  14. Improved IPN error box for GRB021125
  15. IPN BURST POSITION
  16. IPN triangulation of GRB021125 (INTEGRAL BURST)
  17. GRB021125 : A long GRB localized by INTEGRAL
  18. IPN confirmation of the reactivation of SGR1900+14
  19. GRB021113, SPI ACS observation
  20. GRB 021112: Afterglow or Variable Star?
  21. GRB021113: optical observations at Bisei
  22. GRB 021113: Evidence for a Dark Optical Afterglow
  23. GRB021112, BVRI field photometry
  24. GRB 021112: Variable Source in R-band search
  25. GRB021112: Optical Observations
  26. IPN triangulation of GRB021113 (=H2449; annulus)
  27. GRB 021113: Optical observations
  28. GRB 021112: RAPTOR Observations
  29. GRB021113 (=H2449): A Long GRB Localized by HETE
  30. GRB021112 (=H2448): A Long GRB Localized by HETE
  31. GRB 021016: Optical Observations
  32. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  33. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  34. SGR1900+14 activity, November 2-4, 2002
  35. GRB021104: optical observations
  36. Detection of activity from SGR 1900+14 with the RXTE/PCA
  37. IPN triangulation of GRB021027 (single large error box)
  38. IPN triangulation of GRB021027 (two large error boxes)
  39. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  40. GRB 021004: optical observations
  41. IPN triangulation of GRB021023 (small error boc)
  42. GRB 020813; likely host galaxy.
  43. IPN triangulation of GRB021020 (smaller error box)
  44. IPN triangulation of GRB021020
  45. GRB 021008, optical observations
  46. IPN triangulation of GRB021016 (small error box)
  47. IPN triangulation of GRB021014 (large error box)
  48. IPN triangulation of GRB021013 (single error box)
  49. GRB 021004: optical spectroscopy on Oct 11
  50. IPN triangulation of GRB021013 (two small error boxes)
  51. GRB021004: High-resolution optical spectroscopy
  52. XRF 020903: flattening of the optical light curve.
  53. GRB021004, UBVRcIc field photometry update
  54. IPN triangulation of GRB021008 (single error box)
  55. GRB 021004 submm observations
  56. IPN triangulation of GRB021008 (two small error boxes)
  57. GRB021004 Chandra HETG Observations
  58. GRB 021004: Optical/NIR Observations
  59. GRB 021004: Additional V-band Polarimetric Observations
  60. GRB021004: optical observation
  61. GRB 021004: Host Galaxy Star Formation Rate
  62. GRB 021004 submm observations
  63. GRB 021004: WC wind?
  64. GRB021004: NIR and Optical observations
  65. GRB 021004: Optical observations, AUDE network
  66. GRB 021004 - VLA Radio Observations
  67. GRB 021004 - Unusual Radio-to-Submm Spectrum
  68. GRB 021004: optical spectroscopy
  69. IPN triangulation of GRB021007 (annulus)
  70. GRB021004: optical observations and predicted break time
  71. GRB021004: BVRc photometry
  72. GRB021004 radio observation
  73. HETE fluences for GRB021004
  74. GRB 021004: Optical Photometry at 2.5 Days
  75. GRB 021004: polarimetric observations
  76. GRB 021004: V-band Polarimetric Observations
  77. GRB021004: Update Bisei photometric data
  78. IRAM Millimeter detection of GRB 021004
  79. GRB 021004 radio observation
  80. GRB 021004: Optical Photometry at 1.5 Days
  81. GRB021004, BVRcIc field photometry
  82. GRB021004: Optical Spectroscopy
  83. GRB 021004 radio search
  84. XRF020903, BVRI field photometry
  85. XRF020903: TNG and Asiago photometry
  86. GRB 020903: Optical observations at RIKEN
  87. XRF 020903: Correction to GCN 1560
  88. XRF 020903: VRI observations
  89. XRF 020903: R band observations
  90. XRF 020903: Archival Optical Images
  91. Radio Observations of XRF 020903: The Missing Link
  92. XRF 020903: Supernova
  93. IPN triangulation of GRB020923 (two error boxes)
  94. IPN triangulation of GRB020914B
  95. IPN triangulation of GRB020911 (2 large error boxes)
  96. GRB 020305: HST/STIS observations
  97. Confirmation of IPN error box for GRB020910
  98. IPN triangulation of GRB020910
  99. IPN GCN Circulars now to be issued without restriction
  100. Single IPN error box for GRB020904

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