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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

32531 results found.

  1. Fermi-LAT gamma-ray observations of IceCube-230707B
  2. Fermi-LAT gamma-ray observations of IceCube-230707A
  3. LIGO/Virgo/KAGRA S230630am: Updated Sky localization
  4. LIGO/Virgo/KAGRA S230630am: Updated Sky localization
  5. IceCube-230708A: Upper limits from a search for additional neutrino events in IceCube
  6. IceCube-230707B: Upper limits from a search for additional neutrino events in IceCube
  7. IceCube-230707A: Upper limits from a search for additional neutrino events in IceCube
  8. LIGO/Virgo/KAGRA S230709bi: Identification of a GW compact binary merger candidate
  9. LIGO/Virgo/KAGRA S230708cf: Identification of a GW compact binary merger candidate
  10. GRB 230628C: GRID Detection
  11. GRB 230707B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  12. GRB 230707A: Fermi GBM Detection
  13. LIGO/Virgo/KAGRA S230707ai: Identification of a GW compact binary merger candidate
  14. GRB 230707A: Swift ToO observations
  15. GRB 230707A: Swift/BAT-GUANO arcminute localization of a burst
  16. ZTF23aaoohpy/AT2023lcr : HCT follow-up observations
  17. Fermi GRB 230707A: Global MASTER-Net observations report
  18. LIGO/Virgo/KAGRA S230706ah: Updated Sky localization
  19. LIGO/Virgo/KAGRA S230704f: Updated Sky localization
  20. LIGO/Virgo/KAGRA S230630bq: Updated Sky localization
  21. LIGO/Virgo/KAGRA S230702an: Updated Sky localization
  22. GRB 230625A: Detection by GRID
  23. LIGO/Virgo/KAGRA S230529ay: Updated Sky localization and EM Bright Classification
  24. LIGO/Virgo/KAGRA S230706ah: Identification of a GW compact binary merger candidate
  25. LIGO/Virgo/KAGRA S230627c: GECKO optical follow-up observations of host galaxy candidates and ZTF23aaptsuy/AT2023lxu
  26. ZTF23aaoohpy/AT2023lcr: AMI-LA radio detection
  27. GRB 230626A: VZLUSAT-2 detection
  28. LVK S230619bd/GBM-230619: Upper limits from a two-week IceCube neutrino search
  29. GRB 230328B: LBT detection of the likely host galaxy
  30. LIGO/Virgo/KAGRA S230704f: Identification of a GW compact binary merger candidate
  31. Konus-Wind detection of GRB 220623A
  32. LIGO/Virgo/KAGRA S230627c: observations of ZTF23aaptsuy/AT2023lx in AbAO observatory
  33. LIGO/Virgo/KAGRA S230702an: Identification of a GW compact binary merger candidate
  34. GRB 230628E: Swift/UVOT Detection
  35. GRB 230628E: Swift-BAT refined analysis
  36. GRB 230628E: ATCA rapid radio follow-up
  37. LIGO/Virgo/KAGRA S230627c: GRANDMA observations of galaxies and ZTF counterpart candidates
  38. LIGO/Virgo/KAGRA S230630bq: Identification of a GW compact binary merger candidate
  39. IPN triangulation of GRB 230625B (ultra-long)
  40. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
  41. LIGO/Virgo/KAGRA S230630am: Identification of a GW compact binary merger candidate
  42. GRB 230625B: CALET Gamma-Ray Burst Monitor detection
  43. GRB 230628E - VLT spectroscopic observations
  44. ZTF23aaoohpy/AT2023lcr: LBT observations
  45. Fermi GRB 230628C: Global MASTER-Net observations report
  46. GRB 230625B: AstroSat CZTI detection
  47. GRB230628E: VLT optical identification of afterglow candidate
  48. GRB 230628E: Enhanced Swift-XRT position (Correction to name in GCN 34115)
  49. Fermi GRB 230628D: Global MASTER-Net observations report
  50. LIGO/Virgo/KAGRA S230628ax: Identification of a GW compact binary merger candidate
  51. GRB 230628E: LCOGT Optical Upper Limit
  52. GRB 230623B: CALET Gamma-Ray Burst Monitor detection
  53. LIGO/Virgo/KAGRA S230516az: GOTO candidate counterpart GOTO23hu ruled out by Zwicky Transient Facility observations
  54. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  55. LIGO/Virgo/KAGRA S230627c: Additional observations from the Zwicky Transient Facility
  56. GRB 230626A: GRBAlpha detection
  57. AT2023lcr: JCMT SCUBA-2 sub-mm observations
  58. LIGO/Virgo/KAGRA S230527c: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  59. LIGO/Virgo/KAGRA S230627c: ATLAS information on the ZTF candidates
  60. LIGO/Virgo/KAGRA S230627c: Upper limits from Fermi-GBM Observations
  61. Konus-Wind detection of GRB 230616A
  62. LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
  63. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  64. LIGO/Virgo/KAGRA S230627c: Updated Sky localization and EM Bright Classification
  65. LIGO/Virgo/KAGRA S230627c: Identification of a GW compact binary merger candidate
  66. GRB 230618A: Swift-BAT refined analysis
  67. LIGO/Virgo/KAGRA S230624av: Updated Sky localization
  68. GRB 230622A: Swift-BAT refined analysis
  69. INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
  70. ZTF23aaoohpy/AT2023lcr: further SAO RAS observations
  71. ATLAS23msn/ZTF23aaoohpy/AT2023lcr: Zeiss-1000 of Koshka observatory optical observations
  72. LIGO/Virgo/KAGRA S230624av: Identification of a GW compact binary merger candidate
  73. GRB 230623A: Tiled Swift observations
  74. MAXI GRB 230623A: MASTER optical observations
  75. GRB 230623A: Tiled Swift observations
  76. GRB 230622A: ATCA rapid radio follow-up
  77. Swift GRB 230622A: Global MASTER-Net observations report
  78. LIGO/Virgo/KAGRA S230615az: LBT spectroscopic classification of GOTO23hn
  79. LIGO/Virgo/KAGRA S230615az: LBT spectroscopic redshift of the host galaxy of GOTO23hn
  80. ZTF23aaoohpy/AT2023lcr: SAO RAS observations
  81. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  82. Fermi GBM-230619: A soft subthreshold candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
  83. AT2023lcr: VLA radio detection
  84. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  85. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Upper limits from Konus-Wind observations
  86. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  87. ZTF23aaoohpy/AT2023lc: Mondy optical observations
  88. IPN triangulation of GRB 230616A (short)
  89. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  90. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  91. AT2023lcr: Pan-STARRS & ATLAS Observations
  92. ZTF23aaoohpy/AT2023lcr: Keck/LRIS spectroscopy and redshift
  93. ZTF23aaoohpy/AT2023lcr: Xinglong-2.16m optical observations
  94. LIGO/Virgo/KAGRA S230615az: Wendelstein observations of DESI galaxies and GIT candidates
  95. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  96. ZTF23aaoohpy/AT2023lcr: OHP/T193 and OHP/T120 optical follow-up observations
  97. ZTF23aaoohpy/AT2023lcr: GROWTH-India Telescope follow-up observations
  98. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  99. ZTF23aaoohpy/AT2023lcr: GOTO early optical observations and constraint
  100. LIGO/Virgo/KAGRA S230615az: GRANDMA observations of GOTO and GIT candidates

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