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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"

4252 results found.

  1. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
  2. GRB 230628E - VLT spectroscopic observations
  3. Fermi GRB 230628C: Global MASTER-Net observations report
  4. Fermi GRB 230628D: Global MASTER-Net observations report
  5. GRB 230628E: Swift detection of a burst
  6. GRB 230626A: GRBAlpha detection
  7. GRB 230623A: MAXI/GSC detection
  8. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  9. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  10. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  11. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  12. LIGO/Virgo/KAGRA S230615az: Wendelstein observations of DESI galaxies and GIT candidates
  13. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  14. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  15. LIGO/Virgo S230619i: Global MASTER-Net observations report
  16. LIGO/Virgo S230618aq: Global MASTER-Net observations report
  17. LIGO/Virgo S230618y: Global MASTER-Net observations report
  18. LIGO/Virgo S230618s: Global MASTER-Net observations report
  19. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  20. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  21. LIGO/Virgo S230618k: Global MASTER-Net observations report
  22. LIGO/Virgo S230617bc: Global MASTER-Net observations report
  23. LIGO/Virgo S230617aq: Global MASTER-Net observations report
  24. LIGO/Virgo S230617aj: Global MASTER-Net observations report
  25. GRB 230616A: AstroSat CZTI detection
  26. LIGO/Virgo/KAGRA S230529ay: Upper limits from a two-week IceCube neutrino search
  27. LIGO/Virgo S230615be: Global MASTER-Net observations report
  28. LIGO/Virgo S230608aw: Global MASTER-Net observations report
  29. LIGO/Virgo S230609a: Global MASTER-Net observations report
  30. LIGO/Virgo S230608ah: Global MASTER-Net observations report
  31. GRB 230606A: Enhanced Swift-XRT position
  32. GRB 230606A: Swift detection of a burst
  33. GRB 230603A: Fermi GBM Final Real-time Localization
  34. LIGO/Virgo S230601bf: Global MASTER-Net observations report
  35. LIGO/Virgo/KAGRA S230529ay: Upper limits from CALET observations.
  36. LIGO/Virgo/KAGRA S230529ay: AstroSat CZTI non-detection and upper limits
  37. LIGO/Virgo S230529ay: Global MASTER-Net observations report
  38. LIGO/Virgo/KAGRA S230529ay: upper limits from AGILE/MCAL
  39. LIGO/Virgo/KAGRA S230529ay: Coverage and upper limits from MAXI/GSC observations
  40. LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  41. LIGO/Virgo/KAGRA S230529ay: Identification of a GW compact binary merger candidate
  42. LIGO/Virgo S230529p: Global MASTER-Net observations report
  43. GRB 230529A: Fermi GBM Final Real-time Localization
  44. LIGO/Virgo S230525a: Global MASTER-Net observations report
  45. LIGO/Virgo S230522a: Global MASTER-Net observations report
  46. LIGO/Virgo/KAGRA S230522a: 2 counterpart neutrino candidates from IceCube neutrino searches
  47. LIGO/Virgo S230521k: Global MASTER-Net observations report
  48. LIGO/Virgo S230520ae: Global MASTER-Net observations report
  49. LIGO/Virgo/KAGRA S230520ae: Identification of a GW compact binary merger candidate: End-to-End Test
  50. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  51. GRB 230520A: MAXI/GSC detection
  52. LIGO/Virgo/KAGRA S230518h: AstroSat CZTI non-detection and upper limits
  53. GRB 230513A: Zwicky Transient Facility continuous observations of a Fermi Short GRB (Trigger 705709044)
  54. GRB 230512A: Kitab possible afterglow candidate
  55. Fermi trigger No 705565670: Global MASTER-Net observations report
  56. GRB 230506C: SAO RAS optical observations
  57. GRB 230506B: MASTER optical observations
  58. IceCube-Cascade 230430A: Upper limits from a search for additional neutrino events in IceCube
  59. GRB 230426A: VZLUSAT-2 detection
  60. GRB 230426A: AstroSat CZTI detection
  61. Fermi trigger No 704233744: Global MASTER-Net observations report
  62. GRB 230414B: 3.6m DOT Optical observations, slow decay at early epochs
  63. GRB 230414B: Montarrenti Observatory late time optical afterglow detection
  64. GRB 230409B: 3.6m DOT near-infrared detection, afterglow confirmation
  65. Fermi GRB 230414A: Global MASTER-Net observations report
  66. Fermi trigger No 702745263: Global MASTER-Net observations report
  67. GRB 230404A: AstroSat CZTI detection
  68. Fermi GRB 230402A: Global MASTER-Net observations report
  69. IceCube-Cascade 230329A: Upper limits from a search for additional neutrino events in IceCube
  70. GRB 230328B: 3.6m DOT multiband optical observation
  71. Konus-Wind detection of GRB 230328B
  72. GRB 230330A: Fermi GBM Final Real-time Localization
  73. GRB 230328B: Nanshan/NEXT 2nd optical observation
  74. GRB 230328B: Liverpool Telescope afterglow detection
  75. Fermi trigger No 701313046: Global MASTER-Net observations report
  76. Konus-Wind detection of GRB 230309A
  77. Fermi trigger No 701071944: Global MASTER-Net observations report
  78. SGR 1806-20: Correction to GCN 33494
  79. INTEGRAL detection of a burst from SGR 1806-200
  80. GRB 230314A: TURBO Optical Upper Limit
  81. Fermi GRB 230316A: Global MASTER-Net observations report
  82. VZLUSAT-2 detection of SGR 1806-20
  83. Alert from the HAWC Burst Monitor HAWC-230311A
  84. Trigger 1159327: Swift detection of SGR1806-20
  85. Fermi GRB 230310A: Global MASTER-Net observations report
  86. GRB 230228A: VIRT Optical Upper Limit
  87. Improved IPN localization for GRB 230307A
  88. IceCube Alert 230306.46: Global MASTER-Net observations report
  89. GRB 230228A: Swift-BAT refined analysis
  90. Fermi trigger No 699294715: Global MASTER-Net observations report
  91. GRB 230228A: Swift detection of a possibly short burst
  92. Fermi trigger No 699029364: Global MASTER-Net observations report
  93. GRB 230220A: MAXI/GSC detection
  94. IceCube Alert 230217.87: Global MASTER-Net observations report
  95. Fermi trigger No 697904388: Global MASTER-Net observations report
  96. Fermi GRB 230209B: Global MASTER-Net observations report
  97. ZTF23aabmzlp/AT2023azs: Neil Gehrels Swift Observatory X-ray observations
  98. GRB 230204B: 3.6m DOT optical observation
  99. GRB 230205A: Swift detection of a burst
  100. GRB 230204B: MAXI/GSC detection

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