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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

11753 results found.

  1. GRB030329 - Light curve flattening
  2. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  3. GRB 030329: visual observations
  4. GRB030328: X-ray Afterglow Observed with Chandra
  5. GRB 030329, R-band observations, supplement
  6. GRB030329:optical observations by MASTER
  7. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  8. RXTE detection of GRB 030329 afterglow
  9. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  10. GRB 030328: Finding chart
  11. GRB 030328: Optical afterglow candidate
  12. GRB030324, optical observations
  13. GRB030324, Optical Observations
  14. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  15. GRB 030324, optical observations
  16. IPN triangulation of GRB030317 (annulus)
  17. GRB 030227: Optical limit at RIKEN
  18. IPN triangulation of GRB030306 (single small error box)
  19. IPN triangulation of GRB030306 (two small error boxes)
  20. IPN triangulation of GRB030306 (intense; annulus only so far)
  21. GRB030226: Analysis of Chandra data
  22. GRB 030227: fading of candidate optical afterglow 'S1-A'
  23. GRB 030227, possible optical counterpart of XMM-Newton source
  24. GRB030227 - faint tentative OT candidate
  25. GRB 030227: Kyoto optical observation
  26. GRB030227 localized by INTEGRAL
  27. GRB 030226, optical observations
  28. GRB 030226 Optical Spectra and R,I,z' Imaging
  29. GRB030226: Candidate optical afterglow
  30. GRB 030217: Optical Observations at 4, 5, and 6 Days
  31. GRB030217: optical observations
  32. GRB030131: Kiso optical limit for corrected position
  33. GRB030131: Optical limits for corrected position
  34. GRB 030131: afterglow candidate
  35. GRB030131: Optical limit
  36. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  37. GRB 030115, simultaneous observations by BOOTES-1
  38. GRB030115: R-band counterpart of IR candidate
  39. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  40. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  41. GRB 030115, no optical candidate
  42. IPN triangulation of GRB030102B (portion of annulus)
  43. GRB on 20030101 seen by SPI-ACS
  44. GRB021219: a long GRB localized by INTEGRAL
  45. IPN detection of continued activity from SGR1806-20
  46. GRB 021201: Optical Observations
  47. GRB 021211: early break in light curve
  48. GRB021211: Optical observations in CrAO
  49. Chandra observation of the IPN error box of GRB021201 (short/hard)
  50. GRB 021211 Milagro GeV/TeV Observations
  51. GRB021211, OT at 108 s
  52. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  53. HETE 2493: Optical observations
  54. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  55. IPN detection of renewed activity from SGR1806-20
  56. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  57. Improved IPN error box for GRB021125
  58. GRB021125 : A long GRB localized by INTEGRAL
  59. IPN confirmation of the reactivation of SGR1900+14
  60. IPN triangulation of GRB021119 (annulus)
  61. GRB021112: Optical Observations
  62. GRB021113 (=H2449): A Long GRB Localized by HETE
  63. GRB021112 (=H2448): A Long GRB Localized by HETE
  64. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  65. GRB 021004: optical observations
  66. IPN triangulation of GRB021020 (smaller error box)
  67. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  68. IPN triangulation of GRB021020
  69. GRB 021016, optical observations
  70. GRB 021004: VRI observations at TNG: possible break
  71. GRB 021008, optical observations
  72. GRB021016(=H2397): A Long GRB Localized by HETE
  73. GRB021004: NIR and Optical observations
  74. GRB 021004: Optical measurement at OHP
  75. GRB 021004: optical spectroscopy
  76. GRB021004: BVRc photometry
  77. GRB 021004: Optical Photometry at 2.5 Days
  78. GRB 021004 radio observation
  79. GRB 021004: Optical Observations
  80. GRB 021004: Optical Photometry at 1.5 Days
  81. GRB021004, Optical Observations
  82. GRB 021004, optical observations
  83. GRB 021004, SPM optical observations
  84. GRB 021004: steepening of the optical decay slope
  85. XRF020903, BVRI field photometry
  86. GRB 020903: Optical observations at RIKEN
  87. XRF 020903: Supernova
  88. IPN triangulation of GRB020926 (two large error boxes)
  89. GRB020924 (ecliptic latitude-only localization)
  90. IPN triangulation of GRB020923 (two error boxes)
  91. Improved IPN position for GRB020918 (two large error boxes)
  92. IPN triangulation of GRB020911 (2 large error boxes)
  93. INTEGRAL GRBs added to GCN
  94. GRB020812: optical observation
  95. Second epoch K band imaging of GRB 020819
  96. GRB 020812: early time optical observation at Ouda Station
  97. GRB020813: Magellan BVRI Photometry
  98. GRB 020819 : OT candidate - confirmation of non variability
  99. K band observation of GRB 020819
  100. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC

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