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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"

32489 results found.

  1. GRB021211, BVRI field photometry
  2. GRB021211: Optical observations in CrAO
  3. GRB 021211, IR observations
  4. GRB 021211, optical observations
  5. GRB 021211: Optical Observations
  6. GRB021211: Kiso Observations
  7. GRB 021201, optical observations
  8. GRB 021211: Radio Observations
  9. GRB021211: Optical observations
  10. GRB 021201 (short/hard), NOT observations
  11. SUB-MM SEARCH FOR GRB 021211
  12. Chandra observation of the IPN error box of GRB021201 (short/hard)
  13. GRB 021211, R- and I-band observations
  14. GRB021211 - Upper limits from recent and historical observations
  15. GRB021211, OT at 108 s
  16. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  17. HETE 2493: Optical observations
  18. GRB 021125: Radio Observations
  19. IPN triangulation of GRB021206 (small error box)
  20. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  21. GRB021201, BVRcIc field photometry
  22. GRB 021201, Radio Observations
  23. GRB 021201: Optical Observations
  24. GRB 021201: BOOTES simultaneous optical observations
  25. GRB021004, late time optical observations
  26. GRB021004 Chandra Observation
  27. GRB021125 refined position
  28. IPN triangulation of GRB021125B (two large error boxes)
  29. IPN triangulation of GRB021119 (large error box)
  30. Improved IPN error box for GRB021125
  31. IPN BURST POSITION
  32. IPN confirmation of the reactivation of SGR1900+14
  33. GRB021113, SPI ACS observation
  34. GRB 021112: Afterglow or Variable Star?
  35. GRB021113: optical observations at Bisei
  36. GRB 021113: Evidence for a Dark Optical Afterglow
  37. GRB 021112: Variable Source in R-band search
  38. GRB021112: Optical Observations
  39. IPN triangulation of GRB021109 (portion of annulus)
  40. IPN triangulation of GRB021113 (=H2449; annulus)
  41. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  42. GRB 021113: Optical Observations
  43. GRB 021113: Optical Observations
  44. GRB021113 (=H2449): A Long GRB Localized by HETE
  45. GRB 021112: Optical Observations
  46. GRB 021112: R-band search
  47. IPN triangulation of GRB021108 (large error box)
  48. GRB021112 (=H2448): A Long GRB Localized by HETE
  49. GRB 021016: Optical Observations
  50. GRB021004: Near infrared spectroscopy
  51. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  52. Spectropolarimetry of GRB021004
  53. GRB021104: optical observations
  54. GRB021104: Candidate present in DSS
  55. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  56. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  57. IPN triangulation of GRB021025 (portion of annulus)
  58. IPN triangulation of GRB021027 (single large error box)
  59. GRB021004, late-time optical observations
  60. IPN triangulation of GRB021027 (two large error boxes)
  61. GRB 021023: Infrared Imaging
  62. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  63. IPN triangulation of SGR1900+14, October 22 2002
  64. GRB 021004: optical observations
  65. GRB021004: Optical Observations
  66. GRB 020813; likely host galaxy.
  67. IPN triangulation of GRB021020 (smaller error box)
  68. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  69. GRB 021008, radio observations
  70. GRB 021016, optical observations
  71. GRB 021004: VRI observations at TNG: possible break
  72. GRB021016, optical observations
  73. GRB 021008, optical observations
  74. GRB021016(=H2397): A Long GRB Localized by HETE
  75. IPN triangulation of GRB021016 (area corrected)
  76. IPN triangulation of GRB021016 (small error box)
  77. GRB021004: Optical Observations
  78. IPN triangulation of GRB021013 (single error box)
  79. GRB 021004: optical spectroscopy on Oct 11
  80. IPN triangulation of GRB021013 (two small error boxes)
  81. GRB021004: High-resolution optical spectroscopy
  82. XRF 020903: flattening of the optical light curve.
  83. GRB021004, UBVRcIc field photometry update
  84. IPN triangulation of GRB021008 (single error box)
  85. GRB021004: Optical Observations
  86. GRB 021004 submm observations
  87. IPN triangulation of GRB021008 (two small error boxes)
  88. GRB 021004: Optical/NIR Observations
  89. GRB 021004: Additional V-band Polarimetric Observations
  90. GRB021004: optical observation
  91. GRB 021004: Host Galaxy Star Formation Rate
  92. GRB 021004 submm observations
  93. GRB 021004: WC wind?
  94. GRB021004: NIR and Optical observations
  95. GRB 021004: Optical measurement at OHP
  96. GRB 021004: Optical observations, AUDE network
  97. GRB 021004 - VLA Radio Observations
  98. GRB 021004 - Unusual Radio-to-Submm Spectrum
  99. XRF 020903 spectrum
  100. GRB021004: optical observations and predicted break time

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