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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"

28092 results found.

  1. IceCube-230708A: Upper limits from Swift/BAT-GUANO
  2. GRB 230709C: GRBAlpha detection
  3. GRB 230707B: Fermi GBM Observation
  4. LIGO/Virgo/KAGRA S230708z: Identification of a GW compact binary merger candidate
  5. LIGO/Virgo/KAGRA S230708t: Identification of a GW compact binary merger candidate
  6. IceCube-230707A: No candidates detected by Swift-XRT
  7. LIGO/Virgo/KAGRA S230708cf: Updated Sky localization
  8. GRB 230703A detected with multiple GRID detectors
  9. GRB 230709C: BALROG localization (Fermi Trigger 710617111 / GRB 230709735)
  10. LIGO/Virgo/KAGRA S230707ai: Updated Sky localization
  11. Fermi-LAT gamma-ray observations of IceCube-230708A
  12. Fermi-LAT gamma-ray observations of IceCube-230707B
  13. Fermi-LAT gamma-ray observations of IceCube-230707A
  14. LIGO/Virgo/KAGRA S230630am: Updated Sky localization
  15. LIGO/Virgo/KAGRA S230630am: Updated Sky localization
  16. GRB 230709B: BALROG localization (Fermi Trigger 710614579 / GRB 230709706)
  17. IceCube-230708A: Upper limits from a search for additional neutrino events in IceCube
  18. IceCube-230707B: Upper limits from a search for additional neutrino events in IceCube
  19. IceCube-230707A: Upper limits from a search for additional neutrino events in IceCube
  20. LIGO/Virgo/KAGRA S230709bi: Identification of a GW compact binary merger candidate
  21. LIGO/Virgo/KAGRA S230708cf: Identification of a GW compact binary merger candidate
  22. GRB 230707B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  23. GRB 230707A: Swift-XRT observations
  24. GRB 230707A: Fermi GBM Detection
  25. LIGO/Virgo/KAGRA S230707ai: Identification of a GW compact binary merger candidate
  26. GRB 230707A: Swift/BAT-GUANO arcminute localization of a burst
  27. LIGO/Virgo/KAGRA S230706ah: Updated Sky localization
  28. LIGO/Virgo/KAGRA S230704f: Updated Sky localization
  29. LIGO/Virgo/KAGRA S230630bq: Updated Sky localization
  30. LIGO/Virgo/KAGRA S230702an: Updated Sky localization
  31. LIGO/Virgo/KAGRA S230529ay: Updated Sky localization and EM Bright Classification
  32. LIGO/Virgo/KAGRA S230706ah: Identification of a GW compact binary merger candidate
  33. LIGO/Virgo/KAGRA S230627c: GECKO optical follow-up observations of host galaxy candidates and ZTF23aaptsuy/AT2023lxu
  34. ZTF23aaoohpy/AT2023lcr: AMI-LA radio detection
  35. Fermi trigger No 710117592: Global MASTER-Net observations report
  36. GRB 230626A: VZLUSAT-2 detection
  37. LVK S230619bd/GBM-230619: Upper limits from a two-week IceCube neutrino search
  38. GRB 230328B: LBT detection of the likely host galaxy
  39. LIGO/Virgo/KAGRA S230704f: Identification of a GW compact binary merger candidate
  40. GRB 230701B: AstroSat CZTI detection
  41. LIGO/Virgo/KAGRA S230627c: observations of ZTF23aaptsuy/AT2023lx in AbAO observatory
  42. LIGO/Virgo/KAGRA S230702an: Identification of a GW compact binary merger candidate
  43. GRB 230628E: Swift/UVOT Detection
  44. GRB 230628E: Swift-BAT refined analysis
  45. GRB 230701A: Fermi GBM Final Real-time Localization
  46. LIGO/Virgo/KAGRA S230627c: GRANDMA observations of galaxies and ZTF counterpart candidates
  47. LIGO/Virgo/KAGRA low-significance gravitational wave candidate S230701z: one counterpart neutrino candidate from IceCube neutrino searches
  48. LIGO/Virgo/KAGRA S230627c: Upper limits from Swift/BAT-GUANO
  49. LIGO/Virgo/KAGRA S230630bq: Identification of a GW compact binary merger candidate
  50. IPN triangulation of GRB 230625B (ultra-long)
  51. LIGO/Virgo/KAGRA S230630am: Identification of a GW compact binary merger candidate
  52. ZTF23aaoohpy/AT2023lcr: LBT observations
  53. GRB230628E: VLT optical identification of afterglow candidate
  54. GRB 230628E: Swift-XRT refined Analysis
  55. GRB 230628E: Enhanced Swift-XRT position (Correction to name in GCN 34115)
  56. GRB 230628A: Enhanced Swift-XRT position
  57. LIGO/Virgo/KAGRA S230628ax: Identification of a GW compact binary merger candidate
  58. GRB 230628E: LCOGT Optical Upper Limit
  59. GRB 230628E: Swift detection of a burst
  60. GRB 230628D: BALROG localization (Fermi Trigger 709676556 / GRB 230628849)
  61. LIGO/Virgo/KAGRA low-significance gravitational wave candidate S230628aj: one counterpart neutrino candidate from IceCube neutrino searches
  62. GRB 230628B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  63. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  64. LIGO/Virgo/KAGRA S230527c: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  65. LIGO/Virgo/KAGRA S230627c: ATLAS information on the ZTF candidates
  66. LIGO/Virgo/KAGRA S230627c: Upper limits from Fermi-GBM Observations
  67. GRB230626A: Fermi GBM Detection
  68. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  69. LIGO/Virgo/KAGRA S230627c: Updated Sky localization and EM Bright Classification
  70. LIGO/Virgo/KAGRA S230627c: Identification of a GW compact binary merger candidate
  71. GRB 230618A: Swift-BAT refined analysis
  72. GRB 230625B: Swift/BAT-GUANO detection of a long burst
  73. LIGO/Virgo/KAGRA S230624av: Updated Sky localization
  74. GRB 230622A: Swift-BAT refined analysis
  75. GRB 230623A: Swift-XRT observations
  76. INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
  77. ZTF23aaoohpy/AT2023lcr: further SAO RAS observations
  78. ATLAS23msn/ZTF23aaoohpy/AT2023lcr: Zeiss-1000 of Koshka observatory optical observations
  79. GRB 230623B: Swift/BAT-GUANO detection of a long burst outside the coded FOV 
  80. LIGO/Virgo/KAGRA S230624av: Identification of a GW compact binary merger candidate
  81. IceCube-Cascade 230622A: Upper limits from a search for additional neutrino events in IceCube
  82. GRB 230622A: Swift-XRT refined Analysis
  83. GRB 230623A: MAXI/GSC detection
  84. ZTF23aaoohpy/AT2023lcr: SAO RAS observations
  85. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  86. GRB 230622A: Swift detection of a burst
  87. IceCube-Cascade 230621A: Upper limits from a search for additional neutrino events in IceCube
  88. Fermi GBM-230619: A soft subthreshold candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
  89. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  90. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Upper limits from Konus-Wind observations
  91. ZTF23aaoohpy/AT2023lc: Mondy optical observations
  92. IPN triangulation of GRB 230616A (short)
  93. LIGO/Virgo/KAGRA S230619bg: one counterpart neutrino candidate from IceCube neutrino searches
  94. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  95. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  96. AT2023lcr: Pan-STARRS & ATLAS Observations
  97. ZTF23aaoohpy/AT2023lcr: Keck/LRIS spectroscopy and redshift
  98. ZTF23aaoohpy/AT2023lcr: Xinglong-2.16m optical observations
  99. LIGO/Virgo/KAGRA S230615az: Wendelstein observations of DESI galaxies and GIT candidates
  100. ZTF23aaoohpy/AT2023lcr: OHP/T193 and OHP/T120 optical follow-up observations

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