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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"

3926 results found.

  1. LIGO/Virgo G184098: INTEGRAL search of temporally coincident prompt hard X-ray emission
  2. LIGO/Virgo G184098: transient search with VISTA
  3. ANTARES neutrino detection: Fermi GBM Observations
  4. LIGO/Virgo G184098: DESGW followup program
  5. LIGO/Virgo G184098: SkyMapper observations
  6. LIGO/Virgo G184098: TAROT network optical observations
  7. LIGO/Virgo G184098: La Silla - QUEST Followup
  8. LIGO/Virgo G184098: Swift follow-up observations
  9. LIGO/Virgo G184098: MWA Followup
  10. LIGO/Virgo G184098: DESGW followup program
  11. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  12. LIGO/Virgo observing run 1 (O1) starts 2015-09-18 15:00 UTC
  13. LIGO/Virgo G184098: Keck II DEIMOS Spectra of iPTF Optical Candidates
  14. LIGO/Virgo G184098: Nearby Galaxies in Error Circle
  15. LIGO/Virgo G184098: Fermi-GBM ground-based follow-up
  16. LIGO/Virgo G184098: Observations from the TOROS collaboration
  17. LIGO/Virgo G184098: iPTF Optical Transient Candidates
  18. LIGO/Virgo G184098: VST-ESO PARANAL observations
  19. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  20. Instructions for reporting follow-up observations related to LIGO/Virgo G184098
  21. LIGO/Virgo G184098: observations by MASTER
  22. LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
  23. LIGO/Virgo G184098: Swift follow-up observations
  24. LIGO/Virgo G184098: Burst candidate in LIGO engineering run data
  25. GRB 150906B: theoretical estimation of redshift and isotropic energy
  26. Short GRB 150906B: proximity to NGC 3313 galaxy group
  27. IPN Triangulation of GRB 150819B (short / very intense)
  28. V404 Cyg: Fermi GBM observations
  29. Disreqard the recent cluster of Swift-related GCN Circulars
  30. GRB 150430A: Swift detection of a burst
  31. Fermi GBM Observations of Magnetar 4U 0142+61
  32. IPN Triangulation of GRB 150220A
  33. Fermi GBM Observations of SGR 1935+2154
  34. IPN Triangulation of GRB 150127B
  35. IPN Triangulation of GRB 150127A
  36. IPN triangulation of GRB 150118C (short/hard)
  37. IPN Triangulation of GRB 141215A (long/intense)
  38. IPN Triangulation of GRB 141202A (short/hard)
  39. GRB 141121A: three epochs of SAO RAS optical observations
  40. IPN Triangulation of GRB 140901A (short/hard/very intense)
  41. IPN triangulation of GRB 140801A (Fermi trigger 428612396)
  42. GRB 140610A: Swift detection of a burst
  43. IPN Triangulation of GRB 131209A
  44. IPN Triangulation of GRB 131126A (short/hard)
  45. IPN Triangulation of GRB 131125A (short/hard)
  46. GRB 131108A: AGILE/GRID observation
  47. Swift Operations in the event of a US Government shutdown
  48. US Government shutdown may impact GRB operation of GCN
  49. GRB 130822A: nearby galaxy redshifts
  50. IPN Triangulation of long GRB 120916A
  51. Corrections to the Fermi-LAT upper limits for GRB 120807A, 120908A, 120909A, and 120911A
  52. Swift starts a new program to find fainter transients
  53. IPN Triangulation of GRB 120328B (long/intense)
  54. GRB 120316A: Fermi-GBM and Fermi-LAT Observations
  55. IPN Triangulation of GRB 120226A
  56. All GCN Circulars available in a tarfile for data mining
  57. IPN triangulation of GRB110825A (very intense, long-duration)
  58. Fermi-GBM data processing and delivery
  59. GRB 100805A: Xinglong TNT optical observation
  60. Swift-BAT trigger 421695 is likely not astrophysical
  61. IPN triangulation of GRB100324B
  62. GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
  63. Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts
  64. First GLAST Burst Monitor GRB Circulars
  65. Reactivation of SGR 1627-41
  66. procesure for GRB Circular
  67. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  68. Swift-XRT improved positions, and new redshift limits.
  69. GRB 080121 position was incorrect
  70. Disregard the "GRB 071126" position
  71. Swift autonomous slewing re-enabled
  72. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  73. GRB 071003: Possible rebrightening
  74. Update on Swift Status
  75. Swift Status and XRT Calibration Uncertainties
  76. GCN Swift XRT update position notices and enhanced position circulars
  77. Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
  78. GRB 070125: Break in Optical Decay
  79. GRB 060929: Further XRT Refined Analysis
  80. test of new software, grb
  81. GRB 060927: Early color
  82. GRB 060526: Break in X-ray light curve
  83. GRB 051221: Improved astrometry of the IR counterpart
  84. GRB051105: optical observations
  85. GRB 051105a: MDM Observations
  86. Swift-BAT trigger 147918 is not a real GRB
  87. GRB 050721A: Swift-BAT refined analysis
  88. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  89. Retraction of three Swift GRB triggers
  90. GRB 050319: ROTSE-III Refined Analysis
  91. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  92. GRB041006: MASTER optical observations
  93. IBAS GRB Alerts 1978-1980
  94. IPN Summary of SGR1806-20 Activity in 2004
  95. GRB and XRF on April 27, 2004. Detection by Konus-Wind and Helicon (Coronas-F)
  96. On Line Availability of Archival HETE Fregate Data and Lightcurves
  97. GRB 040223 XMM-Newton observation ...
  98. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  99. XRF030723 (=H2777): Second Epoch Magellan Observations
  100. GRBlog: Compilation of all GCN Circ. data

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