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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"

4055 results found.

  1. LIGO/Virgo G194575: LOFAR follow-up
  2. LIGO/Virgo G194575: RATIR Observations of Nearby Galaxies in the 1sigma Error Region
  3. LIGO Virgo G194575: MWA Observations
  4. LIGO/Virgo G194575: INTEGRAL search of temporally coincident prompt hard X-ray emission
  5. LIGO/Virgo G194575: RATIR Observations of Nearby Galaxies in the 1sigma Error Region
  6. LIGO/Virgo G194575: more details on transients from Pan-STARRS in the RA=1hr localisation region
  7. GRB 151022A: Swift-XRT refined Analysis
  8. LIGO/Virgo G194575: Fermi GBM Observations
  9. LIGO/Virgo G194575: Mini-MegaTORTORA observations
  10. LIGO/Virgo G194575: transients from Pan-STARRS in the RA=1hr localisation region
  11. LIGO Virgo G194575: TZAC TAROT observations
  12. LIGO/Virgo G194575: Identification of a GW CBC Candidate
  13. LIGO/Virgo G184098: LOFAR follow-up
  14. LIGO/Virgo G184098: VLA follow-up of iPTF15cyk
  15. LIGO/VIRGO G184098 : PESSTO classifications of PanSTARRS transients in the northern region
  16. LIGO/Virgo G184098: Further VST-ESO PARANAL observations
  17. LIGO/VIRGO G184098 : PESSTO classification of PS15cbm in the northern region
  18. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  19. LIGO/Virgo G184098: MASTER OTs detection and Scenario Machine prediction
  20. LIGO/Virgo G184098: Ongoing gravitational-wave analysis
  21. LIGO/Virgo G184098: spectral classification of PS15cci
  22. LIGO/Virgo G184098: Update to LT Spectroscopy of PS15ccx
  23. LIGO/Virgo G184098: Liverpool Telescope Spectroscopy of PS15ccx
  24. LIGO/Virgo G184098: LOFAR follow-up
  25. LIGO/Virgo G184098: ASKAP followup
  26. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  27. LIGO/Virgo G184098: optical transient search with Kiso Schmidt telescope and KWFC on behalf of J-GEM collaboration
  28. LIGO/VIRGO G184098 : classifications of transients from the LSQ observations
  29. IPN Triangulation of GRB 150922A (short/hard)
  30. LIGO/Virgo G184098: INTEGRAL search of temporally coincident prompt hard X-ray emission
  31. LIGO/Virgo G184098: transient search with VISTA
  32. ANTARES neutrino detection: Fermi GBM Observations
  33. LIGO/Virgo G184098: DESGW followup program
  34. LIGO/Virgo G184098: SkyMapper observations
  35. LIGO/Virgo G184098: TAROT network optical observations
  36. LIGO/Virgo G184098: La Silla - QUEST Followup
  37. LIGO/Virgo G184098: Swift follow-up observations
  38. LIGO/Virgo G184098: MWA Followup
  39. LIGO/Virgo G184098: DESGW followup program
  40. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  41. LIGO/Virgo observing run 1 (O1) starts 2015-09-18 15:00 UTC
  42. LIGO/Virgo G184098: Keck II DEIMOS Spectra of iPTF Optical Candidates
  43. LIGO/Virgo G184098: Nearby Galaxies in Error Circle
  44. LIGO/Virgo G184098: Fermi-GBM ground-based follow-up
  45. LIGO/Virgo G184098: Observations from the TOROS collaboration
  46. LIGO/Virgo G184098: iPTF Optical Transient Candidates
  47. LIGO/Virgo G184098: VST-ESO PARANAL observations
  48. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  49. Instructions for reporting follow-up observations related to LIGO/Virgo G184098
  50. LIGO/Virgo G184098: observations by MASTER
  51. LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
  52. LIGO/Virgo G184098: Swift follow-up observations
  53. LIGO/Virgo G184098: Burst candidate in LIGO engineering run data
  54. GRB 150906B: theoretical estimation of redshift and isotropic energy
  55. Short GRB 150906B: proximity to NGC 3313 galaxy group
  56. IPN Triangulation of GRB 150819B (short / very intense)
  57. V404 Cyg: Fermi GBM observations
  58. Disreqard the recent cluster of Swift-related GCN Circulars
  59. GRB 150430A: Swift detection of a burst
  60. Fermi GBM Observations of Magnetar 4U 0142+61
  61. IPN Triangulation of GRB 150220A
  62. Fermi GBM Observations of SGR 1935+2154
  63. IPN Triangulation of GRB 150127B
  64. IPN Triangulation of GRB 150127A
  65. IPN triangulation of GRB 150118C (short/hard)
  66. IPN Triangulation of GRB 141215A (long/intense)
  67. IPN Triangulation of GRB 141202A (short/hard)
  68. GRB 141121A: three epochs of SAO RAS optical observations
  69. IPN Triangulation of GRB 140901A (short/hard/very intense)
  70. IPN triangulation of GRB 140801A (Fermi trigger 428612396)
  71. GRB 140610A: Swift detection of a burst
  72. IPN Triangulation of GRB 131209A
  73. IPN Triangulation of GRB 131126A (short/hard)
  74. IPN Triangulation of GRB 131125A (short/hard)
  75. GRB 131108A: AGILE/GRID observation
  76. Swift Operations in the event of a US Government shutdown
  77. US Government shutdown may impact GRB operation of GCN
  78. GRB 130822A: nearby galaxy redshifts
  79. IPN Triangulation of long GRB 120916A
  80. Corrections to the Fermi-LAT upper limits for GRB 120807A, 120908A, 120909A, and 120911A
  81. Swift starts a new program to find fainter transients
  82. IPN Triangulation of GRB 120328B (long/intense)
  83. GRB 120316A: Fermi-GBM and Fermi-LAT Observations
  84. IPN Triangulation of GRB 120226A
  85. All GCN Circulars available in a tarfile for data mining
  86. IPN triangulation of GRB110825A (very intense, long-duration)
  87. Fermi-GBM data processing and delivery
  88. GRB 100805A: Xinglong TNT optical observation
  89. Swift-BAT trigger 421695 is likely not astrophysical
  90. IPN triangulation of GRB100324B
  91. GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
  92. Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts
  93. First GLAST Burst Monitor GRB Circulars
  94. Reactivation of SGR 1627-41
  95. procesure for GRB Circular
  96. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  97. Swift-XRT improved positions, and new redshift limits.
  98. GRB 080121 position was incorrect
  99. Disregard the "GRB 071126" position
  100. Swift autonomous slewing re-enabled

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