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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"

32502 results found.

  1. GRB021219, optical observation by MASTER
  2. GRB021219: Correction to GCN 1766
  3. VLT spectra of GRB 021211 revisited
  4. GRB021219: a long GRB localized by INTEGRAL
  5. GRB021211: APO optical observations
  6. IPN detection of continued activity from SGR1806-20
  7. XRF 020903 : HST observations
  8. GRB 021201: Optical Observations
  9. GRB 021211, optical observations
  10. GRB 021211: CTIO observations
  11. GRB021211: Measurement of Early Time Afterglow
  12. VLT spectrum of GRB 021211
  13. GRB 021211: early break in light curve
  14. GRB021211, BVRI field photometry
  15. GRB021211: Optical observations in CrAO
  16. GRB 021211, IR observations
  17. GRB 021211, optical observations
  18. GRB 021211: Optical Observations
  19. GRB021211: Kiso Observations
  20. GRB 021201, optical observations
  21. GRB 021211: Radio Observations
  22. GRB021211: Optical observations
  23. GRB 021201 (short/hard), NOT observations
  24. SUB-MM SEARCH FOR GRB 021211
  25. Chandra observation of the IPN error box of GRB021201 (short/hard)
  26. GRB 021211, R- and I-band observations
  27. GRB021211 - Upper limits from recent and historical observations
  28. GRB021211, OT at 108 s
  29. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  30. HETE 2493: Optical observations
  31. GRB 021125: Radio Observations
  32. IPN triangulation of GRB021206 (small error box)
  33. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  34. GRB021201, BVRcIc field photometry
  35. GRB 021201, Radio Observations
  36. GRB 021201: Optical Observations
  37. GRB 021201: BOOTES simultaneous optical observations
  38. GRB021004, late time optical observations
  39. GRB021004 Chandra Observation
  40. GRB021125 refined position
  41. IPN triangulation of GRB021125B (two large error boxes)
  42. IPN triangulation of GRB021119 (large error box)
  43. Improved IPN error box for GRB021125
  44. IPN BURST POSITION
  45. IPN confirmation of the reactivation of SGR1900+14
  46. GRB021113, SPI ACS observation
  47. GRB 021112: Afterglow or Variable Star?
  48. GRB021113: optical observations at Bisei
  49. GRB 021113: Evidence for a Dark Optical Afterglow
  50. GRB 021112: Variable Source in R-band search
  51. GRB021112: Optical Observations
  52. IPN triangulation of GRB021109 (portion of annulus)
  53. IPN triangulation of GRB021113 (=H2449; annulus)
  54. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  55. GRB 021113: Optical Observations
  56. GRB 021113: Optical Observations
  57. GRB021113 (=H2449): A Long GRB Localized by HETE
  58. GRB 021112: Optical Observations
  59. GRB 021112: R-band search
  60. IPN triangulation of GRB021108 (large error box)
  61. GRB021112 (=H2448): A Long GRB Localized by HETE
  62. GRB 021016: Optical Observations
  63. GRB021004: Near infrared spectroscopy
  64. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  65. Spectropolarimetry of GRB021004
  66. GRB021104: optical observations
  67. GRB021104: Candidate present in DSS
  68. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  69. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  70. IPN triangulation of GRB021025 (portion of annulus)
  71. IPN triangulation of GRB021027 (single large error box)
  72. GRB021004, late-time optical observations
  73. IPN triangulation of GRB021027 (two large error boxes)
  74. GRB 021023: Infrared Imaging
  75. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  76. IPN triangulation of SGR1900+14, October 22 2002
  77. GRB 021004: optical observations
  78. GRB021004: Optical Observations
  79. GRB 020813; likely host galaxy.
  80. IPN triangulation of GRB021020 (smaller error box)
  81. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  82. GRB 021008, radio observations
  83. GRB 021016, optical observations
  84. GRB 021004: VRI observations at TNG: possible break
  85. GRB021016, optical observations
  86. GRB 021008, optical observations
  87. GRB021016(=H2397): A Long GRB Localized by HETE
  88. IPN triangulation of GRB021016 (area corrected)
  89. IPN triangulation of GRB021016 (small error box)
  90. GRB021004: Optical Observations
  91. IPN triangulation of GRB021013 (single error box)
  92. GRB 021004: optical spectroscopy on Oct 11
  93. IPN triangulation of GRB021013 (two small error boxes)
  94. GRB021004: High-resolution optical spectroscopy
  95. XRF 020903: flattening of the optical light curve.
  96. GRB021004, UBVRcIc field photometry update
  97. IPN triangulation of GRB021008 (single error box)
  98. GRB021004: Optical Observations
  99. GRB 021004 submm observations
  100. IPN triangulation of GRB021008 (two small error boxes)

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