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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"

3533 results found.

  1. V404Cyg Swift Trigger 668097: AbAO optical observations
  2. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  3. LIGO/Virgo G211117: List of near-term future observation regions by Project Mini-GWAC of SVOM
  4. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  5. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28, 29
  6. GRB 151228B: Fermi GBM observation
  7. GRB 151228A: MITSuME Akeno optical upper limits
  8. GRB 151228A: T60 observations
  9. LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
  10. GRB 151228A: Fermi GBM observation
  11. LIGO/Virgo G211117: Pan-STARRS1 observations 2015-12-28
  12. LIGO/Virgo G211117: INAF VST-ESO PARANAL observations
  13. GRB 151215A: Swift detection of a burst
  14. GRB 151205C: Optical follow-up observations at Kiso
  15. GRB 130831A: MASTER early OT detection and LC
  16. GRB 151205B: MASTER-NET early optical observations
  17. GRB 151205B: Swift detection of a burst
  18. Fermi GBM trigger 470375959/151128166 is not a GRB
  19. GRB151127A: Planned XMM-Newton observation
  20. GRB 151120A: Swift-XRT afterglow detection
  21. GRB 151120A: GROND optical/NIR afterglow
  22. GRB 151118A: ISON-NM early optical limit
  23. Swift-BAT trigger 663164 is not a burst.
  24. GRB 151107B: MASTER-NET OT detection inside the FERMI error box
  25. LIGO/Virgo G194575: Liverpool Telescope observations of iPTF-15dld and iPTF-15dni
  26. GRB 151107A: MASTER-NET optical observations
  27. GRB 151027A: Mondy optical observations
  28. GRB 151027A: Mt. Terskol observatory optical observation
  29. LIGO/Virgo G194575: LT Spectroscopy of iPTF candidates
  30. GRB 151031A: Swift detection of a burst
  31. GRB 151027A: Continued P60 Monitoring
  32. GRB 151027A: Optical counterpart detection
  33. GRB 151027A: SAO RAS optical observations
  34. GRB 151027B: LCOGT FTN afterglow observations
  35. GRB 151027A : Xinglong TNT optical observation
  36. GRB 151027A: continued GMG observation
  37. GRB 151027A: LCOGT-McDonald afterglow observations
  38. GRB 151027B: GROND Optical/NIR Afterglow Detection
  39. GRB 151027B: VLT/X-shooter redshift
  40. LIGO/Virgo G194575: Kanata/J-GEM optical follow-up
  41. LIGO/Virgo G194575: CQUEAN/LOAO observations
  42. LIGO/Virgo G194575: more details on transients from Pan-STARRS in the RA=1hr localisation region
  43. LIGO/Virgo G194575: transients from Pan-STARRS in the RA=1hr localisation region
  44. Konus-Wind observation of GRB 151021A
  45. GRB 151001B: Swift-BAT refined analysis
  46. GRB 150925A: Swift detection of a burst
  47. LIGO/Virgo G184098: INTEGRAL search of temporally coincident prompt hard X-ray emission
  48. LIGO/Virgo G184098: DESGW followup program
  49. LIGO/Virgo G184098: Keck II DEIMOS Spectra of iPTF Optical Candidates
  50. GRB 150915A: GROND detection of an optical counterpart candidate
  51. Fermi GBM trigger 463890496/150914103 is not a GRB
  52. GRB 150910A: VLA Detection
  53. GRB 150910A: MITSuME Okayama Ks-band Observation
  54. GRB 150910A: Enhanced Swift-XRT position
  55. GRB 150910A: Swift/UVOT Detection of a Brightening Afterglow
  56. GRB 150910A: LCOGT FTN afterglow observations
  57. GRB 150910A: Swift detection of a burst with an optical afterglow
  58. GRB 150907B: MASTER-SAAO early optical observations
  59. GRB 150907A: MAXI/GSC detection
  60. GRB 150901A: Swift detection of a burst
  61. Fermi GBM trigger 150828520 is not a GRB
  62. Swift Trigger 652824 is due to noise
  63. Swift Trigger 652824: Is most likely a noise fluctuation in the direction of M31
  64. GRB 150818A: MITSuME Ishigakijima upper limits
  65. GRB 150818A: Swift/UVOT candidate afterglow
  66. GRB 150818A: Swift detection of a burst
  67. Konus-Wind observation of GRB 150811B
  68. Swift Trigger 652046 is probably not a GRB
  69. GRB 150801A: MAXI/GSC detection
  70. GRB 150728A: RATIR Optical Observations
  71. GRB 150728A: AAO optical observations
  72. GRB 150728A: FTN observations
  73. GRB 150727A: LCOGT-Cerro Tololo observations
  74. GRB 150727A: VLT/X-shooter redshift
  75. Konus-Wind observation of GRB 150725A
  76. Swift IGR J00291+5934: MASTER Optical flare detection
  77. GRB 150720A: Swift-XRT refined Analysis
  78. GRB 150711A: Fermi GBM detection
  79. GRB 150710B refined analysis
  80. GRB 150711A: Swift detection of a burst
  81. Konus-Wind observation of GRB 150710A (Swift trigger 648437)
  82. Swift trigger 648437: A GRB or a burst from 1RXS J125754.7+141850
  83. Fermi Gamma-ray Burst Monitor Trigger bn150628857 is not a GRB
  84. V404 Cyg: MASTER Swift, Integral alert observations
  85. Swift Trigger 645340: a possible GRB
  86. Trigger 645176: Swift detection of V404 Cyg
  87. GRB 150616A: Swift-BAT refined analysis
  88. Optical follow-up of Swift trigger on V404 Cyg
  89. GRB 150615A: Swift detection of a burst
  90. GRB 150530B detected in ground analysis of BAT data
  91. GRB 150513A: Swift detection of a burst
  92. GRB 150430A: MAXI/GSC detection
  93. GRB 150430A: Swift detection of a burst
  94. GRB 150428B: IRSF NIR upper limits
  95. GRB 150428C: MASTER-net automatic optical inspection
  96. GRB 150428B: MASTER-net prompt optical observation
  97. GRB 150428A: MASTER-net early optical observation
  98. GRB 150428A: Danish1.56m optical observations
  99. GRB 150428A: P60 observations
  100. GRB 150428A: GROND Dark Burst Host Candidate

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