文件操作 - 1758093116.M664145P11326.mail.planetcloud-host.com,S=6894,W=7027:2,

文件: /var/vmail/bicar.it/stefano/cur/1758093116.M664145P11326.mail.planetcloud-host.com,S=6894,W=7027:2,

编辑文件内容

Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=174.142.199.243; helo=server.astronomerstelegram.org; envelope-from=atel@astronomerstelegram.org; receiver=stefano@bicar.it 
To: stefano@bicar.it
From: atel@astronomerstelegram.org
Subject: ATel  17391, 17392
Message-Id: <20250917071152.B50A92880886@server.astronomerstelegram.org>
Date: Wed, 17 Sep 2025 03:11:52 -0400 (EDT)

------------------------------------------------------------------------------ 
The Astronomer's Telegram is free to read, free to publish, free to
use.  Thanks to the support of our patrons, we can continue to
keep it free. https://www.patreon.com/astronomerstel
------------------------------------------------------------------------------ 
The Astronomer's Telegram                   http://www.astronomerstelegram.org 
------------------------------------------------------------------------------
Posted: Within the last 24 hours
==============================================================================
ATEL #17391							     ATEL #17391

Title:	Fermi-LAT detection of enhanced gamma-ray activity from the
		FSRQ PKS B0027-024
Author:	F. Longo (University of Trieste and INFN Trieste), A. Holzmann
		Airasca (University of Trento and INFN Bari) and P. Monti-Guarnieri
		(University of Trieste and INFN Trieste), on behalf of the Fermi Large
		Area Telescope Collaboration
Queries:	francesco.longo@ts.infn.it
Posted:	16 Sep 2025; 17:23 UT
Subjects:Gamma Ray, >GeV, AGN

The Large Area Telescope (LAT), one of the two instruments on the Fermi
Gamma-ray Space Telescope, has observed enhanced gamma-ray activity from
a source positionally consistent with the FSRQ PKS B0027-024, also known
as 4FGL J0030.6-0212 (Abdollahi et al. 2022, ApJS, 260, 53), with coordinates
R.A. = 7.63260 deg, Dec. = -2.19893 deg (J2000; Hunt et al. 2021, AJ, 162,
121), and redshift z = 1.804 (Sexton et al. 2022, ApJS, 260, 33).

Preliminary analysis indicates that this source was in an elevated gamma-ray
emission state on September 15, 2025, with a daily averaged gamma-ray flux
(E>100MeV) of (0.6+/-0.1) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty
only). This corresponds to a flux increase of a factor of 20 relative to
the average flux reported in the fourth data release of the fourth Fermi-LAT
catalog (4FGL-DR4, Ballet et al. 2023, arXiv:2307.12546). This is the highest
LAT daily flux ever observed for this source. The corresponding photon
index is 1.8+/-0.1 indicating a significantly harder spectral state than
the one inferred from the average power-law spectral index of 2.41 +/-
0.02 reported in 4FGL-DR4. We observed a photon with an energy of 44 GeV
with a probability p>0.999 to be associated with the flaring source.

Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray
monitoring of this source will continue. A preliminary light curve for
PKS B0027-024 can be accessed via the Fermi-LAT Light-Curve Repository
at <a href="https://fermi.gsfc.nasa.gov/ssc/data/access/lat/LightCurveRepository/source.html?source_name=4FGL_J0030.6-0212">4FGL
J0030.6-0212</a>.  We encourage multifrequency observations of this source.
For this source, the Fermi-LAT contact person is Francesco Longo (Francesco.Longo@ts.infn.it).

The Fermi-LAT is a pair conversion telescope designed to cover the energy
band from 20 MeV to greater than 300 GeV. It is the product of an international
collaboration between NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.

------------------------------------------------------------------------------
Password Certification: Francesco Longo (francesco.longo@ts.infn.it)
https://www.astronomerstelegram.org/?read=17391
==============================================================================
ATEL #17392							     ATEL #17392

Title:	Discovery of a Probable Nova in M31
Author:	K. Hornoch (Ondrejov), M. Wolf (Charles University), A. W.
		Shafter (SDSU)
Queries:	k.hornoch@centrum.cz
Posted:	17 Sep 2025; 05:06 UT
Subjects:Optical, Nova, Transient

We report the discovery of a probable nova found during our survey of the
central 
region of M31. The object was discovered on a co-added 1440-s R-band CCD
frame 
taken on 2025 Sep. 16.863 UT with the 0.65-m telescope at Ondrejov. The
new object 
is faintly visible also on a prediscovery co-added 450-s R-band CCD frame
taken 
on 2025 Sep. 15.818 UT with the same instrumentation.

The object designated PNV J00424264+4111245 is located at R.A. = 0h42m42s.64,

Decl. = +41o11'24".5 (equinox 2000.0), which is 19.0" west and 284.0" south

of the center of M31 (see link to discovery image below).

The following R-band magnitudes were obtained using the 0.65-m telescope
at Ondrejov (D65):

<span class="inner-pre" style="font-size: 13px"> 
Date [UT]    |  Mag   | Err  | Filter  | Telescope

2025-09-13.111 | >19.1  |      | R       | D65 
2025-09-15.818 |  19.7  | 0.25 | R       | D65 
2025-09-16.863 |  18.6  | 0.1  | R       | D65

</span>

As with all extragalactic novae, follow-up spectroscopic and photometric
observations 
to confirm the nova's nature and determine its spectroscopic class and
rate of decline 
(speed class) are encouraged.

Discovery image: http://www.asu.cas.cz/~asteroid/PNVJ00424264+4111245.png
------------------------------------------------------------------------------
Password Certification: Allen W. Shafter (ashafter@sdsu.edu)
https://www.astronomerstelegram.org/?read=17392
==============================================================================

==============================================================================
This is an automatically-generated notice.  You can remove yourself permanently
from receiving both the Daily Email Digest and Instant Email Notices from
The Astronomer's Telegram by following this link:
https://www.astronomerstelegram.org?unsubscribe&confirmation=a803d34e7ea924f9a4142bac00763549&address=stefano@bicar.it

文件操作 - 1758093116.M664145P11326.mail.planetcloud-host.com,S=6894,W=7027:2,

文件: /var/vmail/bicar.it/stefano/cur/1758093116.M664145P11326.mail.planetcloud-host.com,S=6894,W=7027:2,

编辑文件内容

修改文件时间

删除文件