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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"

41200 results found.

  1. GRB040912 : Kiso Optical follow-up observation
  2. IBAS GRB Alerts 1978-1980
  3. Optical observations of field of GRB040912
  4. HETE 3557: Optical observations
  5. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  6. GRB 040827: XMM-Newton data
  7. GRB040903 - A XRF?
  8. GRB040827: analysis of the XMM-Newton observation
  9. GRB040903, REM near-IR observation
  10. GRB 040903 - INTEGRAL data analysis
  11. Very bright burst detected from SGR 1806-20
  12. Possible GRB 040903 detected with INTEGRAL
  13. GRB 040827 - Radio Observations
  14. GRB040825A: Optical observations
  15. GRB040825A: Optical observations
  16. GRB 040827: optical and NIR observations at the VLT
  17. GRB 040827: UKIRT - 2nd epoch K-band imaging
  18. GRB 040827: 2nd epoch of Magellan K-band imaging
  19. GRB 040827: K imaging - no evidence of variability
  20. GRB 040827: Detection of NIR afterglow
  21. GRB 040827: Possible detection of optical afterglow
  22. GRB 040827: RTT150 optical observations
  23. GRB040827 XMM-Newton observation
  24. GRB040825A: optical limit before GRB
  25. MASTER: GRB040827 possible OT
  26. GRB 040825B: Optical observations
  27. GRB040827 optical observations
  28. GRB 040827 : Planned XMM-Newton observation
  29. GRB 040827 - Refined position
  30. GRB 040827 - A long GRB detected by INTEGRAL
  31. GRB040825B, BVRcIc field photometry
  32. GRB040825A, BVRcIc field photometry
  33. GCN GRB OBSERBATION REPORT
  34. GRB 040825A,optical observations
  35. GRB040825A: optical observations
  36. GRB040825B: optical observations
  37. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  38. GRB 040825A: Optical observations.
  39. MASTER: GRB040825a optical observation
  40. MASTER: GRB040825b optical observation
  41. GRB 040825: Optical observations
  42. XRF040812: possible afterglow second Chandra observation
  43. GRB 040812: Second epoch CXO Observations
  44. GRB040823,optical observation
  45. XRF040812: GMRT observations
  46. Triangulation of GRB 040816 (Konus-Wind - Helicon-Coronas-F)
  47. XRF 040812: optical observation at VLT
  48. GRB 040812: Optical counterparts of CXO sources
  49. XRF040812: possible afterglow
  50. CXO observation of GRB 040812
  51. Bursting activity from SGR 1806-20 detected with IBAS
  52. IPN/HETE localizations of GRB040810 (=H3489)
  53. GRB 040812: Keck and LCO optical observations
  54. GRB 040812: Keck and LCO observations
  55. GRB 040812: radio observations
  56. GRB040812, optical/IR observations
  57. GRB 040812: a long GRB detected by INTEGRAL
  58. GRB 040810: Optical observations of a limited region
  59. XRF040701: Optical Observations at ESO
  60. IPN/HETE triangulation of GRB040802 (=H3485)
  61. GRB 040730, infrared observations
  62. GRB 040730: Optical observations
  63. GRB 040730: a long GRB detected with INTEGRAL
  64. Ongoing activity of SGR 1806-20
  65. GRB040624: optical monitoring at TNG
  66. XRF 040701 - optical observations of the decaying Chandra source
  67. XRF040701: Second-Epoch Chandra Observations
  68. Cancellation of IBAS/INTEGRAL GRB alerts
  69. XRF040701: VLA Observations
  70. XRF040701: Magellan Spectroscopy of Chandra Source #2 Associated Galaxy
  71. XRF040701: First-Epoch Chandra Observations
  72. GRB040709 J,H-band observations
  73. GRB040624, optical observations
  74. GRB040706:observation at University of Miyazaki
  75. XRF 040701, optical observations
  76. XRF040701 (=U11548): a bright XRF detected by HETE
  77. GRB 040624: optical observations
  78. Optical Observations of GRB040624
  79. GRB 040624: optical observations at TNG and VLT
  80. MASTER: GRB 040624 optical observation after 0,48d
  81. GRB 040624: R-band observations
  82. GRB 040624, optical observations
  83. GRB 040624 - A long GRB detected with INTEGRAL
  84. GRB 030329: Rebrightening of hyperluminal ejecta.
  85. IPN Summary of SGR1806-20 Activity in 2004
  86. GRB040511: Retraction of redshift identification
  87. SGR 1806-20: no IR variability of the proposed counterparts
  88. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  89. SGR 1806-20, potential NIR counterpart
  90. GRB 040606: Optical observations
  91. MASTER: HETE Alert 3274 optical observation
  92. Activivty of SGR 1806-20
  93. IPN triangulation of an intense intermediate burst from SGR1806-20
  94. GRB 040511, very fast decay?
  95. GRB 030324: Detection and Color of Host Galaxy
  96. GRB 040511: NIR observations with REM
  97. GRB040511: Redshift identifcation
  98. GRB 040511: Optical limit
  99. GRB040511: Candidate optical/NIR afterglow
  100. IBAS GRB Alerts n.1785 to 1791

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