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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"

34069 results found.

  1. GRB 040827: 2nd epoch of Magellan K-band imaging
  2. GRB 040827: K imaging - no evidence of variability
  3. GRB 040827: Detection of NIR afterglow
  4. GRB 040827: Possible detection of optical afterglow
  5. GRB 040827: RTT150 optical observations
  6. GRB040825A: optical limit before GRB
  7. GRB 040825B: Optical observations
  8. GRB040827 optical observations
  9. GRB 040827 : Planned XMM-Newton observation
  10. GRB 040827 - Refined position
  11. GRB 040827 : peak flux
  12. GRB 040827 - A long GRB detected by INTEGRAL
  13. GRB040825B, BVRcIc field photometry
  14. GRB040825A, BVRcIc field photometry
  15. GCN GRB OBSERBATION REPORT
  16. GRB 040825A,optical observations
  17. Increase of SGR 1806-20 activity
  18. GRB 040825A: Optical observations.
  19. GRB040825B: Correction to GCN 2657
  20. GRB 040825: Optical observations
  21. GRB 040812: Second epoch CXO Observations
  22. GRB040823,optical observation
  23. Triangulation of GRB 040816 (Konus-Wind - Helicon-Coronas-F)
  24. XRF 040812: optical observation at VLT
  25. GRB 040812: Optical counterparts of CXO sources
  26. XRF040812: possible afterglow
  27. CXO observation of GRB 040812
  28. IPN/HETE localizations of GRB040810 (=H3489)
  29. GRB 040812: Keck and LCO optical observations
  30. GRB 040812: Keck and LCO observations
  31. GRB 040812: radio observations
  32. GRB040812, optical/IR observations
  33. Konus-Wind observation of GRB040810 (=H3489)
  34. GRB 040812: a long GRB detected by INTEGRAL
  35. GRB 040810: Optical observations of a limited region
  36. XRF040701: Optical Observations at ESO
  37. IPN/HETE triangulation of GRB040802 (=H3485)
  38. GRB 040730, infrared observations
  39. GRB 040730: Optical observations
  40. GRB 040730: a long GRB detected with INTEGRAL
  41. Ongoing activity of SGR 1806-20
  42. GRB040624: optical monitoring at TNG
  43. Cancellation of IBAS/INTEGRAL GRB alerts
  44. IBAS Alert 1836: NOT a real GRB
  45. GRB040709 J,H-band observations
  46. GRB 040624: optical observations
  47. GRB 040624: optical observations at TNG and VLT
  48. MASTER: GRB 040624 optical observation after 0,48d
  49. GRB 040624: R-band observations
  50. GRB 040624, optical observations
  51. GRB 040624 - A long GRB detected with INTEGRAL
  52. GRB 030329: Rebrightening of hyperluminal ejecta.
  53. IPN Summary of SGR1806-20 Activity in 2004
  54. GRB040511: Retraction of redshift identification
  55. SGR 1806-20: no IR variability of the proposed counterparts
  56. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  57. SGR 1806-20, potential NIR counterpart
  58. GRB 040606: Optical observations
  59. MASTER: HETE Alert 3274 optical observation
  60. Activivty of SGR 1806-20
  61. IPN triangulation of an intense intermediate burst from SGR1806-20
  62. GRB 040511, very fast decay?
  63. GRB 030324: Detection and Color of Host Galaxy
  64. GRB 040511: NIR observations with REM
  65. GRB040511: Redshift identifcation
  66. GRB 040511: Optical limit
  67. IBAS GRB Alerts n.1785 to 1791
  68. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  69. GRB 040511: Second Epoch Optical Observations
  70. IBAS GRB Alerts 1781-4
  71. GRB 040511: Optical observations
  72. GRB 040511: Optical Observations
  73. GRB040511: Optical Observations
  74. GRB040511: Optical Observations
  75. GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
  76. IBAS GRB Alert number 1774: NOT a real GRB
  77. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  78. IBAS Alerts 1771 and 1772: NOT a real GRB
  79. GRB and XRF on April 27, 2004. Detection by Konus-Wind and Helicon (Coronas-F)
  80. IPN triangulation of GRB040425 (=H3183)
  81. GRB040422: optical observations at CrAO
  82. GRB 040423 (=H3175): A Long GRB Localized by HETE
  83. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  84. GRB040422, BVRcIc field calibration
  85. GRB 040422,optical observation
  86. GRB040422: optical and NIR observations at the VLT
  87. GRB 040422: a long GRB detected with INTEGRAL
  88. GRB 040403, deep optical observations
  89. INTEGRAL-SPI/ACS GRB data: timing correction
  90. IBAS GRB alerts 1739, 1740, 1741
  91. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  92. GRB 040403: Optical Observations
  93. GRB 040403 Optical Observations
  94. GRB 040403: Optical observations
  95. GRB 040403: optical observations
  96. GRB 040403: Optical Observations
  97. GRB 040403: a long GRB detected with INTEGRAL
  98. GRB 040329: hard burst detected by Konus-Wind and Helicon - Coronas-F
  99. IBAS GRB Alert 1694
  100. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC

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