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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"

41685 results found.

  1. GRB021211: APO optical observations
  2. IPN detection of continued activity from SGR1806-20
  3. XRF 020903 : HST observations
  4. GRB 021201: Optical Observations
  5. GRB 021211, optical observations
  6. GRB 021211: CTIO observations
  7. GRB021211: Measurement of Early Time Afterglow
  8. VLT spectrum of GRB 021211
  9. GRB 021211: early break in light curve
  10. GRB021211, BVRI field photometry
  11. GRB021211: Optical observations in CrAO
  12. GRB 021211, IR observations
  13. GRB 021211, optical observations
  14. GRB 021211: Optical Observations
  15. GRB021211: Kiso Observations
  16. GRB021204: Kiso Observations
  17. GRB 021201, optical observations
  18. GRB 021211: Radio Observations
  19. GRB021211: Optical observations
  20. GRB 021201 (short/hard), NOT observations
  21. SUB-MM SEARCH FOR GRB 021211
  22. Chandra observation of the IPN error box of GRB021201 (short/hard)
  23. GRB 021211, R- and I-band observations
  24. GRB021211 - Upper limits from recent and historical observations
  25. GRB021211, OT at 108 s
  26. GRB021211 (HETE2493), OT at 143 sec
  27. GRB 021204: I-band Observations
  28. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  29. HETE 2493: Optical observations
  30. GRB 021125: Radio Observations
  31. IPN triangulation of GRB021206 (small error box)
  32. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  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. Radio Catalog of GRB Afterglows
  39. GRB021004, late time optical observations
  40. GRB021004 Chandra Observation
  41. GRB021125 refined position
  42. IPN triangulation of GRB021125B (two large error boxes)
  43. IPN triangulation of GRB021119 (large error box)
  44. Improved IPN error box for GRB021125
  45. IPN BURST POSITION
  46. GRB021125 : A long GRB localized by INTEGRAL
  47. IPN confirmation of the reactivation of SGR1900+14
  48. GRB021113, SPI ACS observation
  49. GRB 021112: Afterglow or Variable Star?
  50. GRB021113: optical observations at Bisei
  51. GRB 021113: Evidence for a Dark Optical Afterglow
  52. GRB021112, BVRI field photometry
  53. GRB 021112: Variable Source in R-band search
  54. GRB021112: Optical Observations
  55. IPN triangulation of GRB021109 (portion of annulus)
  56. IPN triangulation of GRB021113 (=H2449; annulus)
  57. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  58. GRB 021112: RAPTOR Observations
  59. GRB 021113: Optical Observations
  60. GRB 021113: Optical Observations
  61. GRB021113 (=H2449): A Long GRB Localized by HETE
  62. GRB 021112: Optical Observations
  63. GRB 021112: R-band search
  64. IPN triangulation of GRB021108 (large error box)
  65. GRB021112 (=H2448): A Long GRB Localized by HETE
  66. GRB 021016: Optical Observations
  67. IPN triangulation of GRB021109 (annulus)
  68. GRB021004: Near infrared spectroscopy
  69. GRB021104: Optical Observations
  70. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  71. SGR1900+14 activity, November 2-4, 2002
  72. Spectropolarimetry of GRB021004
  73. GRB021104: Optical observations
  74. GRB021104: optical observations
  75. GRB021104: Candidate present in DSS
  76. GRB021104: possible optical afterglow
  77. Detection of activity from SGR 1900+14 with the RXTE/PCA
  78. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  79. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  80. IPN triangulation of GRB021025 (portion of annulus)
  81. IPN triangulation of GRB021027 (single large error box)
  82. GRB021004, late-time optical observations
  83. IPN triangulation of GRB021027 (two large error boxes)
  84. GRB 021023: Infrared Imaging
  85. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  86. IPN triangulation of SGR1900+14, October 22 2002
  87. GRB 021004: optical observations
  88. GRB021004: Optical Observations
  89. GRB 020813; likely host galaxy.
  90. IPN triangulation of GRB021020 (smaller error box)
  91. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  92. GRB 021008, radio observations
  93. GRB 021016, optical observations
  94. GRB 021004: VRI observations at TNG: possible break
  95. GRB021016, optical observations
  96. SGR1900+14: burst on October 10 2002
  97. GRB 021008, optical observations
  98. GRB021016(=H2397): A Long GRB Localized by HETE
  99. IPN triangulation of GRB021016 (area corrected)
  100. IPN triangulation of GRB021016 (small error box)

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