GRB 250830B: Swift observation summary

Mission:	MAXI
GRB RA:	105.723°
GRB Dec:	-64.816°
GRB Err:	3.0 arcmin
T0:	2025-08-30 03:56:44 UT
Galactic:	275.39° -23.19°
Galactic N_H:	7.99× 10²⁰ cm^-2
Galactic E(B-V):	0.1043312

Sun distance:	83.56°
Sun angle:	3.53 [hr](West of Sun)
Moon distance:	82.10°
Visibility of this field.

Data analysed so far:

ObsID: 00021858001 with 0.8 ks exposure.
ObsID: 00021858002 with 1.6 ks exposure.

Source 1 has been manually confirmed as the GRB afterglow; data for this object are now available through the main GRB results area for this GRB.

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Sources found so far

So far 2 sources have been found in the XRT data. 1 sources match catalogued sources.

#	RA (J2000)	Dec (J2000)	Err₉₀¹	Detection Flag²	Dist from MAXI pos	Exposure	Notes
1 [details]	07h 02m 57.59s105.73994°	-64° 51′ 09.1″-64.85252°	3.7′′	Good	2.2′	6.0 ks
Mean XRT rate: 2.00 (±0.24) ×10^-2 ct s^-1 Peak XRT rate: 3.5 (±0.9) ×10^-2 ct s^-1 RASS PSPC 3-σ upper limit: 0.02 ct s^-1 (XRT equiv count-rate) Mean XRT flux: 8.4 (±1.0) ×10^-13 erg cm^-1s^-1 Peak XRT flux: 1.5 (±0.4) ×10^-12 erg cm^-1s^-1 Products: Light curve \| Spectrum \| Enhanced position \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?]
2 [details]	07h 03m 01.99s105.75829°	-64° 58′ 43.9″-64.97885°	11.2′′	Good	9.8′	6.0 ks	Matches SIMBAD source: TYC 8916-607-1, 26.3″ away.
Mean XRT rate: 6.5 (+1.7, -1.6) ×10^-3 ct s^-1 Peak XRT rate: 9 (±3) ×10^-3 ct s^-1 RASS PSPC 3-σ upper limit: 0.04 ct s^-1 (XRT equiv count-rate) Mean XRT flux: 3.5 (+0.9, -0.8) ×10^-13 erg cm^-1s^-1 Peak XRT flux: 4.6 (±1.7) ×10^-13 erg cm^-1s^-1 Products: Spectrum \| Enhanced position \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?]

¹ Radius, 90% confidence.
² Indicates how likely the source is to be real. See the 1SXPS documentation.
^* The position was enhanced using astrometry derived from the Swift UVOT.
^† The position was astrometrically corrected using the XRT sources and the 2MASS catalogue.

Image

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FITS image.

Exposure map

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FITS exposure map.