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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"

26499 results found.

  1. XRF 040916, optical follow-up
  2. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  3. GRB040916: Optical observations
  4. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  5. GRB 040912: Optical Observations
  6. GRB/XRF040912,optical observations
  7. GRB 040912, BVRI observations
  8. Optical observations of GRB/XRF 040912 = HETE 3557
  9. GRB040912 : Kiso Optical follow-up observation
  10. Optical observations of field of GRB040912
  11. HETE 3557: Optical observations
  12. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  13. GRB040903 - A XRF?
  14. GRB040827: analysis of the XMM-Newton observation
  15. GRB040903, REM near-IR observation
  16. Very bright burst detected from SGR 1806-20
  17. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  18. GRB 040827 - Radio Observations
  19. XMM-Newton Images of GRB 040827
  20. GRB040825A: Optical observations
  21. GRB040825A: Optical observations
  22. GRB 040827: optical and NIR observations at the VLT
  23. GRB 040827: UKIRT - 2nd epoch K-band imaging
  24. GRB 040827: 2nd epoch of Magellan K-band imaging
  25. GRB 040827: K imaging - no evidence of variability
  26. GRB 040827: Detection of NIR afterglow
  27. GRB 040827: RTT150 optical observations
  28. GRB040827 XMM-Newton observation
  29. GRB040825A: optical limit before GRB
  30. GRB 040825B: Optical observations
  31. GRB 040827 : Planned XMM-Newton observation
  32. GRB040825B, BVRcIc field photometry
  33. GRB040825A, BVRcIc field photometry
  34. GCN GRB OBSERBATION REPORT
  35. GRB 040825A,optical observations
  36. Increase of SGR 1806-20 activity
  37. GRB040825A: optical observations
  38. GRB040825B: optical observations
  39. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  40. GRB 040825A: Optical observations.
  41. GRB040825B: Correction to GCN 2657
  42. XRF040812: possible afterglow second Chandra observation
  43. GRB 040812: Second epoch CXO Observations
  44. GRB040823,optical observation
  45. XRF040812: GMRT observations
  46. XRF 040812: optical observation at VLT
  47. GRB 040812: Optical counterparts of CXO sources
  48. XRF040812: possible afterglow
  49. CXO observation of GRB 040812
  50. Bursting activity from SGR 1806-20 detected with IBAS
  51. GRB 040812: Keck and LCO optical observations
  52. GRB 040812: Keck and LCO observations
  53. GRB 040812: radio observations
  54. GRB040812, optical/IR observations
  55. GRB 040812: a long GRB detected by INTEGRAL
  56. GRB 040810: Optical observations of a limited region
  57. XRF040701: Optical Observations at ESO
  58. IPN/HETE triangulation of GRB040802 (=H3485)
  59. GRB 040730, infrared observations
  60. GRB 040730: a long GRB detected with INTEGRAL
  61. Ongoing activity of SGR 1806-20
  62. GRB040624: optical monitoring at TNG
  63. XRF 040701 - optical observations of the decaying Chandra source
  64. XRF040701: Second-Epoch Chandra Observations
  65. XRF040701: VLA Observations
  66. XRF040701: Magellan Spectroscopy of Chandra Source #2 Associated Galaxy
  67. XRF040701: First-Epoch Chandra Observations
  68. GRB040709 J,H-band observations
  69. GRB040624, optical observations
  70. GRB040706:observation at University of Miyazaki
  71. XRF 040701, optical observations
  72. XRF040701 (=U11548): a bright XRF detected by HETE
  73. Optical Observations of GRB040624
  74. GRB 040624: optical observations at TNG and VLT
  75. MASTER: GRB 040624 optical observation after 0,48d
  76. GRB 040624: R-band observations
  77. GRB 040624, optical observations
  78. GRB 030329: Rebrightening of hyperluminal ejecta.
  79. IPN Summary of SGR1806-20 Activity in 2004
  80. SGR 1806-20: no IR variability of the proposed counterparts
  81. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  82. GRB 040606: Optical observations
  83. MASTER: HETE Alert 3274 optical observation
  84. Activivty of SGR 1806-20
  85. IPN triangulation of an intense intermediate burst from SGR1806-20
  86. GRB 040511, very fast decay?
  87. GRB 030324: Detection and Color of Host Galaxy
  88. GRB 040511: NIR observations with REM
  89. GRB040511: Redshift identifcation
  90. GRB040511: Candidate optical/NIR afterglow
  91. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  92. GRB 040511: Second Epoch Optical Observations
  93. GRB 040511: Optical observations
  94. GRB 040511: Optical Observations
  95. GRB040511: Optical Observations
  96. GRB040511: Optical Observations
  97. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  98. GRB 040423 (=H3175): A Long GRB Localized by HETE
  99. GRB040422, optical observations at Loiano
  100. GRB040422 : I-band follow-up observation at Lulin Observatory

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