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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"

27409 results found.

  1. GRB021211, BVRI field photometry
  2. GRB021211: Optical observations in CrAO
  3. GRB 021211, optical observations
  4. GRB021211: Kiso Observations
  5. GRB 021201, optical observations
  6. GRB021211: Optical observations
  7. GRB 021201 (short/hard), NOT observations
  8. SUB-MM SEARCH FOR GRB 021211
  9. Chandra observation of the IPN error box of GRB021201 (short/hard)
  10. GRB 021211, R- and I-band observations
  11. GRB021211 - Upper limits from recent and historical observations
  12. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  13. IPN triangulation of GRB021206 (small error box)
  14. IPN triangulation of GRB021205 (large error box)
  15. GRB021201, BVRcIc field photometry
  16. GRB 021201: BOOTES simultaneous optical observations
  17. IPN triangulation of GRB021201 (short/hard burst, small error box)
  18. GRB021004, late time optical observations
  19. GRB021004 Chandra Observation
  20. IPN detection of continued SGR1900+14 activity
  21. Improved IPN error box for GRB021125
  22. IPN BURST POSITION
  23. IPN triangulation of GRB021125 (INTEGRAL BURST)
  24. GRB021125 : A long GRB localized by INTEGRAL
  25. IPN confirmation of the reactivation of SGR1900+14
  26. GRB021113, SPI ACS observation
  27. GRB 021112: Afterglow or Variable Star?
  28. GRB021113: optical observations at Bisei
  29. GRB 021113: Evidence for a Dark Optical Afterglow
  30. GRB021112, BVRI field photometry
  31. GRB 021112: Variable Source in R-band search
  32. GRB021112: Optical Observations
  33. IPN triangulation of GRB021113 (=H2449; annulus)
  34. GRB 021113: Optical observations
  35. GRB 021112: RAPTOR Observations
  36. GRB021113 (=H2449): A Long GRB Localized by HETE
  37. GRB021112 (=H2448): A Long GRB Localized by HETE
  38. GRB 021016: Optical Observations
  39. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  40. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  41. SGR1900+14 activity, November 2-4, 2002
  42. GRB021104: optical observations
  43. Detection of activity from SGR 1900+14 with the RXTE/PCA
  44. IPN triangulation of GRB021027 (single large error box)
  45. IPN triangulation of GRB021027 (two large error boxes)
  46. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  47. GRB 021004: optical observations
  48. IPN triangulation of GRB021023 (small error boc)
  49. GRB 020813; likely host galaxy.
  50. IPN triangulation of GRB021020 (smaller error box)
  51. IPN triangulation of GRB021020
  52. GRB 021008, optical observations
  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. XRF 020903: flattening of the optical light curve.
  60. GRB021004, UBVRcIc field photometry update
  61. IPN triangulation of GRB021008 (single error box)
  62. GRB 021004 submm observations
  63. IPN triangulation of GRB021008 (two small error boxes)
  64. GRB021004 Chandra HETG Observations
  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. GRB021004: NIR and Optical observations
  72. GRB 021004: Optical observations, AUDE network
  73. GRB 021004 - VLA Radio Observations
  74. GRB 021004 - Unusual Radio-to-Submm Spectrum
  75. GRB 021004: optical spectroscopy
  76. IPN triangulation of GRB021007 (annulus)
  77. GRB021004: optical observations and predicted break time
  78. GRB021004: BVRc photometry
  79. GRB021004 radio observation
  80. HETE fluences for GRB021004
  81. GRB 021004: Optical Photometry at 2.5 Days
  82. GRB 021004: polarimetric observations
  83. GRB 021004: V-band Polarimetric Observations
  84. GRB021004: Update Bisei photometric data
  85. IRAM Millimeter detection of GRB 021004
  86. GRB 021004 radio observation
  87. GRB 021004: Optical Photometry at 1.5 Days
  88. GRB021004, BVRcIc field photometry
  89. GRB021004: Optical Spectroscopy
  90. GRB 021004 radio search
  91. XRF020903, BVRI field photometry
  92. XRF020903: TNG and Asiago photometry
  93. GRB 020903: Optical observations at RIKEN
  94. XRF 020903: Correction to GCN 1560
  95. XRF 020903: VRI observations
  96. XRF 020903: R band observations
  97. XRF 020903: Archival Optical Images
  98. Radio Observations of XRF 020903: The Missing Link
  99. XRF 020903: Supernova
  100. IPN triangulation of GRB020923 (two error boxes)

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